diff --git a/cli/attachmentinfo.cpp b/cli/attachmentinfo.cpp
index 3d13865..51b90ff 100644
--- a/cli/attachmentinfo.cpp
+++ b/cli/attachmentinfo.cpp
@@ -5,6 +5,7 @@
 
 #include <c++utilities/conversion/conversionexception.h>
 #include <c++utilities/conversion/stringconversion.h>
+#include <c++utilities/conversion/stringbuilder.h>
 
 #include <cstring>
 #include <iostream>
@@ -37,7 +38,7 @@ void AttachmentInfo::parseDenotation(const char *denotation)
     }
 }
 
-void AttachmentInfo::apply(AbstractContainer *container)
+void AttachmentInfo::apply(AbstractContainer *container, Media::Diagnostics &diag)
 {
     static const string context("applying specified attachments");
     AbstractAttachment *attachment = nullptr;
@@ -48,30 +49,30 @@ void AttachmentInfo::apply(AbstractContainer *container)
             cerr << "Argument --update-argument specified but no name/path provided." << endl;
             return;
         }
-        apply(container->createAttachment());
+        apply(container->createAttachment(), diag);
         break;
     case AttachmentAction::Update:
         if(hasId) {
             for(size_t i = 0, count = container->attachmentCount(); i < count; ++i) {
                 attachment = container->attachment(i);
                 if(attachment->id() == id) {
-                    apply(attachment);
+                    apply(attachment, diag);
                     attachmentFound = true;
                 }
             }
             if(!attachmentFound) {
-                container->addNotification(NotificationType::Critical, "Attachment with the specified ID \"" + numberToString(id) + "\" does not exist and hence can't be updated.", context);
+                diag.emplace_back(DiagLevel::Critical, argsToString("Attachment with the specified ID \"", id, "\" does not exist and hence can't be updated."), context);
             }
         } else if(name) {
             for(size_t i = 0, count = container->attachmentCount(); i < count; ++i) {
                 attachment = container->attachment(i);
                 if(attachment->name() == name) {
-                    apply(attachment);
+                    apply(attachment, diag);
                     attachmentFound = true;
                 }
             }
             if(!attachmentFound) {
-                container->addNotification(NotificationType::Critical, "Attachment with the specified name \"" + string(name) + "\" does not exist and hence can't be updated.", context);
+                diag.emplace_back(DiagLevel::Critical, argsToString("Attachment with the specified name \"", name, "\" does not exist and hence can't be updated."), context);
             }
         } else {
             cerr << "Argument --update-argument specified but no ID/name provided." << endl;
@@ -87,7 +88,7 @@ void AttachmentInfo::apply(AbstractContainer *container)
                 }
             }
             if(!attachmentFound) {
-                container->addNotification(NotificationType::Critical, "Attachment with the specified ID \"" + numberToString(id) + "\" does not exist and hence can't be removed.", context);
+                diag.emplace_back(DiagLevel::Critical, "Attachment with the specified ID \"" + numberToString(id) + "\" does not exist and hence can't be removed.", context);
             }
         } else if(name) {
             for(size_t i = 0, count = container->attachmentCount(); i < count; ++i) {
@@ -98,7 +99,7 @@ void AttachmentInfo::apply(AbstractContainer *container)
                 }
             }
             if(!attachmentFound) {
-                container->addNotification(NotificationType::Critical, "Attachment with the specified name \"" + string(name) + "\" does not exist and hence can't be removed.", context);
+                diag.emplace_back(DiagLevel::Critical, "Attachment with the specified name \"" + string(name) + "\" does not exist and hence can't be removed.", context);
             }
         } else {
             cerr << "Argument --remove-argument specified but no ID/name provided." << endl;
@@ -107,13 +108,13 @@ void AttachmentInfo::apply(AbstractContainer *container)
     }
 }
 
-void AttachmentInfo::apply(AbstractAttachment *attachment)
+void AttachmentInfo::apply(AbstractAttachment *attachment, Media::Diagnostics &diag)
 {
     if(hasId) {
         attachment->setId(id);
     }
     if(path) {
-        attachment->setFile(path);
+        attachment->setFile(path, diag);
     }
     if(name) {
         attachment->setName(name);
@@ -134,13 +135,13 @@ void AttachmentInfo::reset()
     path = name = mime = desc = nullptr;
 }
 
-bool AttachmentInfo::next(AbstractContainer *container)
+bool AttachmentInfo::next(AbstractContainer *container, Media::Diagnostics &diag)
 {
     if(!id && !path && !name && !mime && !desc) {
         // skip empty attachment infos
         return false;
     }
-    apply(container);
+    apply(container, diag);
     reset();
     return true;
 }
diff --git a/cli/attachmentinfo.h b/cli/attachmentinfo.h
index 281bef8..30a9a93 100644
--- a/cli/attachmentinfo.h
+++ b/cli/attachmentinfo.h
@@ -1,6 +1,8 @@
 #ifndef CLI_ATTACHMENT_INFO
 #define CLI_ATTACHMENT_INFO
 
+#include <tagparser/diagnostics.h>
+
 #include <c++utilities/conversion/types.h>
 
 namespace Media {
@@ -21,10 +23,10 @@ class AttachmentInfo
 public:
     AttachmentInfo();
     void parseDenotation(const char *denotation);
-    void apply(Media::AbstractContainer *container);
-    void apply(Media::AbstractAttachment *attachment);
+    void apply(Media::AbstractContainer *container, Media::Diagnostics &diag);
+    void apply(Media::AbstractAttachment *attachment, Media::Diagnostics &diag);
     void reset();
-    bool next(Media::AbstractContainer *container);
+    bool next(Media::AbstractContainer *container, Media::Diagnostics &diag);
 
     AttachmentAction action;
     uint64 id;
diff --git a/cli/helper.cpp b/cli/helper.cpp
index e28f733..2aef21c 100644
--- a/cli/helper.cpp
+++ b/cli/helper.cpp
@@ -2,6 +2,8 @@
 #include "./fieldmapping.h"
 
 #include <tagparser/mediafileinfo.h>
+#include <tagparser/diagnostics.h>
+#include <tagparser/progressfeedback.h>
 #include <tagparser/matroska/matroskatag.h>
 #include <tagparser/mp4/mp4tag.h>
 #include <tagparser/vorbis/vorbiscomment.h>
@@ -118,16 +120,16 @@ string incremented(const string &str, unsigned int toIncrement)
     return res;
 }
 
-void printNotifications(NotificationList &notifications, const char *head, bool beVerbose)
+void printDiagMessages(const Diagnostics &diag, const char *head, bool beVerbose)
 {
-    if(notifications.empty()) {
+    if(diag.empty()) {
         return;
     }
     if(!beVerbose) {
-        for(const auto &notification : notifications) {
-            switch(notification.type()) {
-            case NotificationType::Debug:
-            case NotificationType::Information:
+        for(const auto &message : diag) {
+            switch(message.level()) {
+            case DiagLevel::Debug:
+            case DiagLevel::Information:
                 break;
             default:
                 goto printNotifications;
@@ -140,45 +142,37 @@ printNotifications:
     if(head) {
         cout << " - " << head << endl;
     }
-    Notification::sortByTime(notifications);
-    for(const auto &notification : notifications) {
-        switch(notification.type()) {
-        case NotificationType::Debug:
+    for(const auto &message : diag) {
+        switch(message.level()) {
+        case DiagLevel::Debug:
             if(beVerbose) {
                 cout << "    Debug        ";
                 break;
             } else {
                 continue;
             }
-        case NotificationType::Information:
+        case DiagLevel::Information:
             if(beVerbose) {
                 cout << "    Information  ";
                 break;
             } else {
                 continue;
             }
-        case NotificationType::Warning:
+        case DiagLevel::Warning:
             cout << "    Warning      ";
             break;
-        case NotificationType::Critical:
+        case DiagLevel::Critical:
             cout << "    Error        ";
             break;
         default:
             ;
         }
-        cout << notification.creationTime().toString(DateTimeOutputFormat::TimeOnly) << "   ";
-        cout << notification.context() << ": ";
-        cout << notification.message() << '\n';
+        cout << message.creationTime().toString(DateTimeOutputFormat::TimeOnly) << "   ";
+        cout << message.context() << ": ";
+        cout << message.message() << '\n';
     }
 }
 
-void printNotifications(const MediaFileInfo &fileInfo, const char *head, bool beVerbose)
-{
-    NotificationList notifications;
-    fileInfo.gatherRelatedNotifications(notifications);
-    printNotifications(notifications, head, beVerbose);
-}
-
 void printProperty(const char *propName, const char *value, const char *suffix, Indentation indentation)
 {
     if(!*value) {
@@ -658,29 +652,23 @@ bool stringToBool(const string &str)
 }
 
 bool logLineFinalized = true;
-static string lastLoggedStatus;
-void logStatus(const StatusProvider &statusProvider)
+static string lastStep;
+void logNextStep(const AbortableProgressFeedback &progress)
 {
-    if(statusProvider.currentStatus() != lastLoggedStatus) {
-        // the ongoing operation ("status") has changed
-        //  -> finalize previous line and make new line
-        if(!logLineFinalized) {
-            cout << "\r - [100%] " << lastLoggedStatus << endl;
-            logLineFinalized = true;
-        }
-        // -> update lastStatus
-        lastLoggedStatus = statusProvider.currentStatus();
+    // finalize previous step
+    if(!logLineFinalized) {
+        cout << "\r - [100%] " << lastStep << endl;
+        logLineFinalized = true;
     }
+    // print line for next step
+    lastStep = progress.step();
+    cout << "\r - [" << setw(3) << static_cast<unsigned int>(progress.stepPercentage()) << "%] " << lastStep << flush;
+    logLineFinalized = false;
+}
 
-    // update current line if an operation is ongoing (status is not empty)
-    if(!lastLoggedStatus.empty()) {
-        int percentage = static_cast<int>(statusProvider.currentPercentage() * 100);
-        if(percentage < 0) {
-            percentage = 0;
-        }
-        cout << "\r - [" << setw(3) << percentage << "%] " << lastLoggedStatus << flush;
-        logLineFinalized = false;
-    }
+void logStepPercentage(const Media::AbortableProgressFeedback &progress)
+{
+    cout << "\r - [" << setw(3) << static_cast<unsigned int>(progress.stepPercentage()) << "%] " << lastStep << flush;
 }
 
 void finalizeLog()
@@ -688,9 +676,9 @@ void finalizeLog()
     if(logLineFinalized) {
         return;
     }
-    cout << '\n';
+    cout << "\r - [100%] " << lastStep << '\n';
     logLineFinalized = true;
-    lastLoggedStatus.clear();
+    lastStep.clear();
 }
 
 }
diff --git a/cli/helper.h b/cli/helper.h
index 039c24f..16fa89e 100644
--- a/cli/helper.h
+++ b/cli/helper.h
@@ -22,6 +22,8 @@ class Argument;
 
 namespace Media {
 class MediaFileInfo;
+class Diagnostics;
+class AbortableProgressFeedback;
 enum class TagUsage;
 enum class ElementPosition;
 }
@@ -263,8 +265,7 @@ constexpr bool isDigit(char c)
 
 std::string incremented(const std::string &str, unsigned int toIncrement = 1);
 
-void printNotifications(NotificationList &notifications, const char *head = nullptr, bool beVerbose = false);
-void printNotifications(const MediaFileInfo &fileInfo, const char *head = nullptr, bool beVerbose = false);
+void printDiagMessages(const Media::Diagnostics &diag, const char *head = nullptr, bool beVerbose = false);
 void printProperty(const char *propName, const char *value, const char *suffix = nullptr, ApplicationUtilities::Indentation indentation = 4);
 void printProperty(const char *propName, ElementPosition elementPosition, const char *suffix = nullptr, ApplicationUtilities::Indentation indentation = 4);
 
@@ -310,7 +311,8 @@ FieldDenotations parseFieldDenotations(const ApplicationUtilities::Argument &fie
 std::string tagName(const Tag *tag);
 bool stringToBool(const std::string &str);
 extern bool logLineFinalized;
-void logStatus(const StatusProvider &statusProvider);
+void logNextStep(const Media::AbortableProgressFeedback &progress);
+void logStepPercentage(const Media::AbortableProgressFeedback &progress);
 void finalizeLog();
 
 }
diff --git a/cli/mainfeatures.cpp b/cli/mainfeatures.cpp
index 2aed726..28e3866 100644
--- a/cli/mainfeatures.cpp
+++ b/cli/mainfeatures.cpp
@@ -18,6 +18,8 @@
 #include <tagparser/abstractattachment.h>
 #include <tagparser/abstractchapter.h>
 #include <tagparser/backuphelper.h>
+#include <tagparser/diagnostics.h>
+#include <tagparser/progressfeedback.h>
 
 #ifdef TAGEDITOR_JSON_EXPORT
 # include <reflective_rapidjson/json/reflector.h>
@@ -107,18 +109,21 @@ void generateFileInfo(const ArgumentOccurrence &, const Argument &inputFileArg,
         MediaFileInfo inputFileInfo(inputFileArg.values().front());
         inputFileInfo.setForceFullParse(validateArg.isPresent());
         inputFileInfo.open(true);
-        inputFileInfo.parseEverything();
+        Diagnostics diag;
+        inputFileInfo.parseEverything(diag);
+
+        // generate and save info
+        Diagnostics diagReparsing;
         (outputFileArg.isPresent() ? cout : cerr) << "Saving file info for \"" << inputFileArg.values().front() << "\" ..." << endl;
-        NotificationList origNotify;
-        if(outputFileArg.isPresent()) {
-            QFile file(fromNativeFileName(outputFileArg.values().front()));
-            if(file.open(QFile::WriteOnly) && file.write(HtmlInfo::generateInfo(inputFileInfo, origNotify)) && file.flush()) {
-                cout << "File information has been saved to \"" << outputFileArg.values().front() << "\"." << endl;
-            } else {
-                cerr << Phrases::Error << "An IO error occured when writing the file \"" << outputFileArg.values().front() << "\"." << Phrases::EndFlush;
-            }
+        if(!outputFileArg.isPresent()) {
+            cout << HtmlInfo::generateInfo(inputFileInfo, diag, diagReparsing).data() << endl;
+            return;
+        }
+        QFile file(fromNativeFileName(outputFileArg.values().front()));
+        if(file.open(QFile::WriteOnly) && file.write(HtmlInfo::generateInfo(inputFileInfo, diag, diagReparsing)) && file.flush()) {
+            cout << "File information has been saved to \"" << outputFileArg.values().front() << "\"." << endl;
         } else {
-            cout << HtmlInfo::generateInfo(inputFileInfo, origNotify).data() << endl;
+            cerr << Phrases::Error << "An IO error occured when writing the file \"" << outputFileArg.values().front() << "\"." << Phrases::EndFlush;
         }
     } catch(const Media::Failure &) {
         cerr << Phrases::Error << "A parsing failure occured when reading the file \"" << inputFileArg.values().front() << "\"." << Phrases::EndFlush;
@@ -146,14 +151,15 @@ void displayFileInfo(const ArgumentOccurrence &, const Argument &filesArg, const
 
     MediaFileInfo fileInfo;
     for(const char *file : filesArg.values()) {
+        Diagnostics diag;
         try {
             // parse tags
             fileInfo.setPath(file);
             fileInfo.open(true);
-            fileInfo.parseContainerFormat();
-            fileInfo.parseTracks();
-            fileInfo.parseAttachments();
-            fileInfo.parseChapters();
+            fileInfo.parseContainerFormat(diag);
+            fileInfo.parseTracks(diag);
+            fileInfo.parseAttachments(diag);
+            fileInfo.parseChapters(diag);
 
             // print general/container-related info
             cout << "Technical information for \"" << file << "\":\n";
@@ -176,8 +182,8 @@ void displayFileInfo(const ArgumentOccurrence &, const Argument &filesArg, const
                 printProperty("Duration", container->duration());
                 printProperty("Creation time", container->creationTime());
                 printProperty("Modification time", container->modificationTime());
-                printProperty("Tag position", container->determineTagPosition());
-                printProperty("Index position", container->determineIndexPosition());
+                printProperty("Tag position", container->determineTagPosition(diag));
+                printProperty("Index position", container->determineIndexPosition(diag));
             }
             if(fileInfo.paddingSize()) {
                 printProperty("Padding", dataSizeToString(fileInfo.paddingSize()));
@@ -295,7 +301,7 @@ void displayFileInfo(const ArgumentOccurrence &, const Argument &filesArg, const
             cerr << Phrases::Error << "An IO failure occured when reading the file \"" << file << "\"." << Phrases::EndFlush;
         }
 
-        printNotifications(fileInfo, "Parsing notifications:", verboseArg.isPresent());
+        printDiagMessages(diag, "Diagnostic messages:", verboseArg.isPresent());
         cout << endl;
     }
 }
@@ -315,12 +321,13 @@ void displayTagInfo(const Argument &fieldsArg, const Argument &filesArg, const A
 
     MediaFileInfo fileInfo;
     for(const char *file : filesArg.values()) {
+        Diagnostics diag;
         try {
             // parse tags
             fileInfo.setPath(file);
             fileInfo.open(true);
-            fileInfo.parseContainerFormat();
-            fileInfo.parseTags();
+            fileInfo.parseContainerFormat(diag);
+            fileInfo.parseTags(diag);
             cout << "Tag information for \"" << file << "\":\n";
             const auto tags = fileInfo.tags();
             if(!tags.empty()) {
@@ -353,7 +360,7 @@ void displayTagInfo(const Argument &fieldsArg, const Argument &filesArg, const A
             ::IoUtilities::catchIoFailure();
             cerr << Phrases::Error << "An IO failure occured when reading the file \"" << file << "\"." << Phrases::EndFlush;
         }
-        printNotifications(fileInfo, "Parsing notifications:", verboseArg.isPresent());
+        printDiagMessages(diag, "Diagnostic messages:", verboseArg.isPresent());
         cout << endl;
     }
 }
@@ -454,17 +461,16 @@ void setTagInfo(const SetTagInfoArgs &args)
 
     // iterate through all specified files
     unsigned int fileIndex = 0;
-    static const string context("setting tags");
-    NotificationList notifications;
+    static string context("setting tags");
     for(const char *file : args.filesArg.values()) {
+        Diagnostics diag;
         try {
             // parse tags and tracks (tracks are relevent because track meta-data such as language can be changed as well)
             cout << TextAttribute::Bold << "Setting tag information for \"" << file << "\" ..." << Phrases::EndFlush;
-            notifications.clear();
             fileInfo.setPath(file);
-            fileInfo.parseContainerFormat();
-            fileInfo.parseTags();
-            fileInfo.parseTracks();
+            fileInfo.parseContainerFormat(diag);
+            fileInfo.parseTags(diag);
+            fileInfo.parseTracks(diag);
             vector<Tag *> tags;
 
             // remove tags with the specified targets
@@ -517,7 +523,7 @@ void setTagInfo(const SetTagInfoArgs &args)
             // alter tags
             fileInfo.tags(tags);
             if(tags.empty()) {
-                fileInfo.addNotification(NotificationType::Critical, "Can not create appropriate tags for file.", context);
+                diag.emplace_back(DiagLevel::Critical, "Can not create appropriate tags for file.", context);
             } else {
                 // iterate through all tags
                 for(auto *tag : tags) {
@@ -534,7 +540,7 @@ void setTagInfo(const SetTagInfoArgs &args)
                     if(!tag->canEncodingBeUsed(denotedEncoding)) {
                         usedEncoding = tag->proposedTextEncoding();
                         if(args.encodingArg.isPresent()) {
-                            fileInfo.addNotification(NotificationType::Warning, argsToString("Can't use specified encoding \"", args.encodingArg.values().front(), "\" in ", tagName(tag), " because the tag format/version doesn't support it."), context);
+                            diag.emplace_back(DiagLevel::Warning, argsToString("Can't use specified encoding \"", args.encodingArg.values().front(), "\" in ", tagName(tag), " because the tag format/version doesn't support it."), context);
                         }
                     }
                     // iterate through all denoted field values
@@ -553,8 +559,9 @@ void setTagInfo(const SetTagInfoArgs &args)
                                         try {
                                             // assume the file refers to a picture
                                             MediaFileInfo fileInfo(relevantDenotedValue->value);
+                                            Diagnostics diag;
                                             fileInfo.open(true);
-                                            fileInfo.parseContainerFormat();
+                                            fileInfo.parseContainerFormat(diag);
                                             auto buff = make_unique<char []>(fileInfo.size());
                                             fileInfo.stream().seekg(0);
                                             fileInfo.stream().read(buff.get(), fileInfo.size());
@@ -562,10 +569,10 @@ void setTagInfo(const SetTagInfoArgs &args)
                                             value.setMimeType(fileInfo.mimeType());
                                             convertedValues.emplace_back(move(value));
                                         } catch(const Media::Failure &) {
-                                            fileInfo.addNotification(NotificationType::Critical, "Unable to parse specified cover file.", context);
+                                            diag.emplace_back(DiagLevel::Critical, "Unable to parse specified cover file.", context);
                                         } catch(...) {
                                             ::IoUtilities::catchIoFailure();
-                                            fileInfo.addNotification(NotificationType::Critical, "An IO error occured when parsing the specified cover file.", context);
+                                            diag.emplace_back(DiagLevel::Critical, "An IO error occured when parsing the specified cover file.", context);
                                         }
                                     } else {
                                         convertedValues.emplace_back(relevantDenotedValue->value, TagTextEncoding::Utf8, usedEncoding);
@@ -579,7 +586,7 @@ void setTagInfo(const SetTagInfoArgs &args)
                             try {
                                 denotedScope.field.setValues(tag, tagType, convertedValues);
                             } catch(const ConversionException &e) {
-                                fileInfo.addNotification(NotificationType::Critical, argsToString("Unable to parse denoted field ID \"", denotedScope.field.name(), "\": ", e.what()), context);
+                                diag.emplace_back(DiagLevel::Critical, argsToString("Unable to parse denoted field ID \"", denotedScope.field.name(), "\": ", e.what()), context);
                             }
                         }
                     }
@@ -613,10 +620,10 @@ void setTagInfo(const SetTagInfoArgs &args)
                             } else if(field.denotes("default")) {
                                 track->setDefault(stringToBool(value));
                             } else {
-                                fileInfo.addNotification(NotificationType::Critical, argsToString("Denoted track property name \"", field.denotation(), "\" is invalid"), argsToString("setting meta-data of track ", track->id()));
+                                diag.emplace_back(DiagLevel::Critical, argsToString("Denoted track property name \"", field.denotation(), "\" is invalid"), argsToString("setting meta-data of track ", track->id()));
                             }
                         } catch(const ConversionException &e) {
-                            fileInfo.addNotification(NotificationType::Critical, argsToString("Unable to parse value for track property \"", field.denotation(), "\": ", e.what()), argsToString("setting meta-data of track ", track->id()));
+                            diag.emplace_back(DiagLevel::Critical, argsToString("Unable to parse value for track property \"", field.denotation(), "\": ", e.what()), argsToString("setting meta-data of track ", track->id()));
                         }
                     }
                 }
@@ -635,7 +642,7 @@ void setTagInfo(const SetTagInfoArgs &args)
             bool attachmentsModified = false;
             if(args.addAttachmentArg.isPresent() || args.updateAttachmentArg.isPresent() || args.removeAttachmentArg.isPresent() || args.removeExistingAttachmentsArg.isPresent()) {
                 static const string context("setting attachments");
-                fileInfo.parseAttachments();
+                fileInfo.parseAttachments(diag);
                 if(fileInfo.attachmentsParsingStatus() == ParsingStatus::Ok) {
                     if(container) {
                         // ignore all existing attachments if argument is specified
@@ -652,24 +659,24 @@ void setTagInfo(const SetTagInfoArgs &args)
                             for(const char *value : args.addAttachmentArg.values(i)) {
                                 currentInfo.parseDenotation(value);
                             }
-                            attachmentsModified |= currentInfo.next(container);
+                            attachmentsModified |= currentInfo.next(container, diag);
                         }
                         currentInfo.action = AttachmentAction::Update;
                         for(size_t i = 0, occurrences = args.updateAttachmentArg.occurrences(); i != occurrences; ++i) {
                             for(const char *value : args.updateAttachmentArg.values(i)) {
                                 currentInfo.parseDenotation(value);
                             }
-                            attachmentsModified |= currentInfo.next(container);
+                            attachmentsModified |= currentInfo.next(container, diag);
                         }
                         currentInfo.action = AttachmentAction::Remove;
                         for(size_t i = 0, occurrences = args.removeAttachmentArg.occurrences(); i != occurrences; ++i) {
                             for(const char *value : args.removeAttachmentArg.values(i)) {
                                 currentInfo.parseDenotation(value);
                             }
-                            attachmentsModified |= currentInfo.next(container);
+                            attachmentsModified |= currentInfo.next(container, diag);
                         }
                     } else {
-                        fileInfo.addNotification(NotificationType::Critical, "Unable to assign attachments because the container object has not been initialized.", context);
+                        diag.emplace_back(DiagLevel::Critical, "Unable to assign attachments because the container object has not been initialized.", context);
                     }
                 } else {
                     // notification will be added by the file info automatically
@@ -677,22 +684,14 @@ void setTagInfo(const SetTagInfoArgs &args)
             }
 
             // apply changes
+            fileInfo.setSaveFilePath(currentOutputFile != noMoreOutputFiles ? string(*currentOutputFile) : string());
             try {
-                // save parsing notifications because notifications of sub objects like tags, tracks, ... will be gone after applying changes
-                fileInfo.setSaveFilePath(currentOutputFile != noMoreOutputFiles ? string(*currentOutputFile) : string());
-                fileInfo.gatherRelatedNotifications(notifications);
-                fileInfo.invalidateNotifications();
+                // create handler for progress updates and aborting
+                AbortableProgressFeedback progress(logNextStep, logStepPercentage);
+                const InterruptHandler handler(bind(&AbortableProgressFeedback::tryToAbort, ref(progress)));
 
-                // register handler for logging status
-                fileInfo.registerCallback(logStatus);
-
-                // register interrupt handler
-                const InterruptHandler handler([&fileInfo] {
-                    fileInfo.tryToAbort();
-                });
-
-                // apply changes and gather notifications
-                fileInfo.applyChanges();
+                // apply changes
+                fileInfo.applyChanges(diag, progress);
 
                 // notify about completion
                 finalizeLog();
@@ -714,8 +713,7 @@ void setTagInfo(const SetTagInfoArgs &args)
             cerr << " - " << Phrases::Error << "An IO failure occured when reading/writing the file \"" << file << "\"." << Phrases::EndFlush;
         }
 
-        fileInfo.gatherRelatedNotifications(notifications);
-        printNotifications(notifications, "Notifications:", args.verboseArg.isPresent());
+        printDiagMessages(diag, "Diagnostic messages:", args.verboseArg.isPresent());
 
         // continue with next file
         ++fileIndex;
@@ -747,6 +745,7 @@ void extractField(const Argument &fieldArg, const Argument &attachmentArg, const
 
     MediaFileInfo inputFileInfo;
     for(const char *file : inputFilesArg.values()) {
+        Diagnostics diag;
         try {
             // setup media file info
             inputFileInfo.setPath(file);
@@ -756,8 +755,8 @@ void extractField(const Argument &fieldArg, const Argument &attachmentArg, const
             if(!fieldDenotations.empty()) {
                 // extract tag field
                 (outputFileArg.isPresent() ? cout : cerr) << "Extracting field " << fieldArg.values().front() << " of \"" << file << "\" ..." << endl;
-                inputFileInfo.parseContainerFormat();
-                inputFileInfo.parseTags();
+                inputFileInfo.parseContainerFormat(diag);
+                inputFileInfo.parseTags(diag);
                 auto tags = inputFileInfo.tags();
                 vector<pair<const TagValue *, string> > values;
                 // iterate through all tags
@@ -769,7 +768,7 @@ void extractField(const Argument &fieldArg, const Argument &attachmentArg, const
                                 values.emplace_back(value, joinStrings({tag->typeName(), numberToString(values.size())}, "-", true));
                             }
                         } catch(const ConversionException &e) {
-                            inputFileInfo.addNotification(NotificationType::Critical, "Unable to parse denoted field ID \"" % string(fieldDenotation.first.field.name()) % "\": " + e.what(), "extracting field");
+                            diag.emplace_back(DiagLevel::Critical, argsToString("Unable to parse denoted field ID \"", fieldDenotation.first.field.name(), "\": ", e.what()), "extracting field");
                         }
                     }
                 }
@@ -812,8 +811,8 @@ void extractField(const Argument &fieldArg, const Argument &attachmentArg, const
                 }
                 logStream << " of \"" << file << "\" ..." << endl;
 
-                inputFileInfo.parseContainerFormat();
-                inputFileInfo.parseAttachments();
+                inputFileInfo.parseContainerFormat(diag);
+                inputFileInfo.parseAttachments(diag);
                 vector<pair<const AbstractAttachment *, string> > attachments;
                 // iterate through all attachments
                 for(const AbstractAttachment *attachment : inputFileInfo.attachments()) {
@@ -856,7 +855,7 @@ void extractField(const Argument &fieldArg, const Argument &attachmentArg, const
             ::IoUtilities::catchIoFailure();
             cerr << Phrases::Error << "An IO failure occured when reading the file \"" << file << "\"." << Phrases::End;
         }
-        printNotifications(inputFileInfo, "Parsing notifications:", verboseArg.isPresent());
+        printDiagMessages(diag, "Diagnostic messages:", verboseArg.isPresent());
     }
 }
 
@@ -877,13 +876,14 @@ void exportToJson(const ArgumentOccurrence &, const Argument &filesArg, const Ar
 
     // gather tags for each file
     for(const char *file : filesArg.values()) {
+        Diagnostics diag;
         try {
             // parse tags
             fileInfo.setPath(file);
             fileInfo.open(true);
-            fileInfo.parseContainerFormat();
-            fileInfo.parseTags();
-            fileInfo.parseTracks();
+            fileInfo.parseContainerFormat(diag);
+            fileInfo.parseTags(diag);
+            fileInfo.parseTracks(diag);
             jsonData.emplace_back(fileInfo, document.GetAllocator());
         } catch(const Media::Failure &) {
             cerr << Phrases::Error << "A parsing failure occured when reading the file \"" << file << "\"." << Phrases::EndFlush;
@@ -893,6 +893,8 @@ void exportToJson(const ArgumentOccurrence &, const Argument &filesArg, const Ar
         }
     }
 
+    // TODO: serialize diag messages
+
     // print the gathered data as JSON document
     ReflectiveRapidJSON::JsonReflector::push(jsonData, document, document.GetAllocator());
     RAPIDJSON_NAMESPACE::OStreamWrapper osw(cout);
diff --git a/gui/attachmentsedit.cpp b/gui/attachmentsedit.cpp
index 88389ac..a3ff7e3 100644
--- a/gui/attachmentsedit.cpp
+++ b/gui/attachmentsedit.cpp
@@ -6,6 +6,7 @@
 
 #include <tagparser/mediafileinfo.h>
 #include <tagparser/abstractattachment.h>
+#include <tagparser/diagnostics.h>
 
 #include <qtutilities/misc/conversion.h>
 
@@ -91,16 +92,17 @@ void AttachmentsEdit::invalidate()
 
 void AttachmentsEdit::addFile(const QString &path)
 {
-    if(fileInfo() && fileInfo()->attachmentsParsingStatus() == ParsingStatus::Ok && fileInfo()->container()) {
-        // create and add attachment
-        auto *attachment = fileInfo()->container()->createAttachment();
-        attachment->setIgnored(true);
-        attachment->setFile(toNativeFileName(path).data());
-        m_addedAttachments << attachment;
-        m_model->addAttachment(-1, attachment, true, path);
-    } else {
+    if(!fileInfo() || fileInfo()->attachmentsParsingStatus() != ParsingStatus::Ok || !fileInfo()->container()) {
         throw Failure();
     }
+    // create and add attachment
+    auto *const attachment = fileInfo()->container()->createAttachment();
+    attachment->setIgnored(true);
+    Diagnostics diag;
+    attachment->setFile(toNativeFileName(path).data(), diag);
+    // TODO: show diag messages
+    m_addedAttachments << attachment;
+    m_model->addAttachment(-1, attachment, true, path);
 }
 
 void AttachmentsEdit::showFileSelection()
diff --git a/gui/fileinfomodel.cpp b/gui/fileinfomodel.cpp
index a9ac2ab..9a12206 100644
--- a/gui/fileinfomodel.cpp
+++ b/gui/fileinfomodel.cpp
@@ -11,7 +11,7 @@
 #include <tagparser/mp4/mp4container.h>
 #include <tagparser/abstracttrack.h>
 #include <tagparser/abstractattachment.h>
-#include <tagparser/notification.h>
+#include <tagparser/diagnostics.h>
 
 #include <c++utilities/chrono/datetime.h>
 #include <c++utilities/conversion/stringconversion.h>
@@ -30,6 +30,7 @@ using namespace std;
 using namespace ChronoUtilities;
 using namespace ConversionUtilities;
 using namespace Media;
+using namespace Utility;
 
 namespace QtGui {
 
@@ -115,34 +116,33 @@ private:
     QStandardItem *m_item;
 };
 
-void addNotifications(Media::NotificationList *notifications, QStandardItem *parent)
+void addDiagMessages(Media::Diagnostics *diag, QStandardItem *parent)
 {
-    Notification::sortByTime(*notifications);
-    for(Notification &notification : *notifications) {
+    for(const auto &msg : *diag) {
         QList<QStandardItem *> notificationRow;
         notificationRow.reserve(3);
 
-        auto *firstItem = defaultItem(QString::fromUtf8(notification.creationTime().toString().data()));
-        switch(notification.type()) {
-        case NotificationType::None:
-            break;
-        case NotificationType::Debug:
+        auto *firstItem = defaultItem(QString::fromUtf8(msg.creationTime().toString().data()));
+        switch(msg.level()) {
+        case DiagLevel::None:
+        case DiagLevel::Debug:
             firstItem->setIcon(FileInfoModel::debugIcon());
             break;
-        case NotificationType::Information:
+        case DiagLevel::Information:
             firstItem->setIcon(FileInfoModel::informationIcon());
             break;
-        case NotificationType::Warning:
+        case DiagLevel::Warning:
             firstItem->setIcon(FileInfoModel::warningIcon());
             break;
-        case NotificationType::Critical:
+        case DiagLevel::Critical:
+        case DiagLevel::Fatal:
             firstItem->setIcon(FileInfoModel::errorIcon());
             break;
         }
         parent->appendRow(QList<QStandardItem *>()
                           << firstItem
-                          << defaultItem(QString::fromUtf8(notification.message().data()))
-                          << defaultItem(QString::fromUtf8(notification.context().data())));
+                          << defaultItem(QString::fromUtf8(msg.message().data()))
+                          << defaultItem(QString::fromUtf8(msg.context().data())));
     }
 
 }
@@ -190,10 +190,9 @@ template<class ElementType, bool isAdditional = false> void addElementNode(const
 /*!
  * \brief Constructs a new instance with the specified \a fileInfo which might be nullptr.
  */
-FileInfoModel::FileInfoModel(Media::MediaFileInfo *fileInfo, QObject *parent) :
+FileInfoModel::FileInfoModel(QObject *parent) :
     QStandardItemModel(parent)
 {
-    setFileInfo(fileInfo);
 }
 
 QVariant FileInfoModel::headerData(int section, Qt::Orientation orientation, int role) const
@@ -231,10 +230,11 @@ const MediaFileInfo *FileInfoModel::fileInfo() const
  * \brief Assigns a Media::MediaFileInfo.
  * \remarks Causes updating the internal cache and resets the model.
  */
-void FileInfoModel::setFileInfo(MediaFileInfo *fileInfo, Media::NotificationList *originalNotifications)
+void FileInfoModel::setFileInfo(MediaFileInfo &fileInfo, Diagnostics &diag, Diagnostics *diagReparsing)
 {
-    m_file = fileInfo;
-    m_originalNotifications = originalNotifications;
+    m_file = &fileInfo;
+    m_diag = &diag;
+    m_diagReparsing = diagReparsing;
     updateCache();
 }
 
@@ -271,6 +271,9 @@ void FileInfoModel::updateCache()
     beginResetModel();
     clear();
     if(m_file) {
+        // get diag
+        Diagnostics &diag = m_diagReparsing ? *m_diagReparsing : *m_diag;
+
         // get container
         AbstractContainer *container = m_file->container();
 
@@ -327,8 +330,8 @@ void FileInfoModel::updateCache()
             containerHelper.appendRow(tr("Document type"), container->documentType());
             containerHelper.appendRow(tr("Document version"), container->doctypeVersion());
             containerHelper.appendRow(tr("Document read version"), container->doctypeReadVersion());
-            containerHelper.appendRow(tr("Tag position"), Utility::elementPositionToQString(container->determineTagPosition()));
-            containerHelper.appendRow(tr("Index position"), Utility::elementPositionToQString(container->determineIndexPosition()));
+            containerHelper.appendRow(tr("Tag position"), Utility::elementPositionToQString(container->determineTagPosition(diag)));
+            containerHelper.appendRow(tr("Index position"), Utility::elementPositionToQString(container->determineIndexPosition(diag)));
         }
         containerHelper.appendRow(tr("Padding size"), m_file->paddingSize());
 
@@ -338,7 +341,7 @@ void FileInfoModel::updateCache()
             if(!tags.empty()) {
                 auto *tagsItem = defaultItem(tr("Tags"));
                 setItem(++currentRow, tagsItem);
-                setItem(currentRow, 1, defaultItem(tr("%1 tag(s) assigned", nullptr, static_cast<int>(tags.size())).arg(tags.size())));
+                setItem(currentRow, 1, defaultItem(tr("%1 tag(s) assigned", nullptr, trQuandity(tags.size())).arg(tags.size())));
 
                 for(const Tag *tag : tags) {
                     auto *tagItem = defaultItem(tag->typeName());
@@ -360,9 +363,9 @@ void FileInfoModel::updateCache()
                 setItem(++currentRow, tracksItem);
                 const string summary(m_file->technicalSummary());
                 if(summary.empty()) {
-                    setItem(currentRow, 1, defaultItem(tr("%1 track(s) contained", nullptr, static_cast<int>(tracks.size())).arg(tracks.size())));
+                    setItem(currentRow, 1, defaultItem(tr("%1 track(s) contained", nullptr, trQuandity(tracks.size())).arg(tracks.size())));
                 } else {
-                    setItem(currentRow, 1, defaultItem(tr("%1 track(s): ", nullptr, static_cast<int>(tracks.size())).arg(tracks.size()) + QString::fromUtf8(summary.data(), summary.size())));
+                    setItem(currentRow, 1, defaultItem(tr("%1 track(s): ", nullptr, trQuandity(tracks.size())).arg(tracks.size()) + QString::fromUtf8(summary.data(), summary.size())));
                 }
 
                 size_t number = 0;
@@ -461,7 +464,7 @@ void FileInfoModel::updateCache()
             if(!attachments.empty()) {
                 auto *attachmentsItem = defaultItem(tr("Attachments"));
                 setItem(++currentRow, attachmentsItem);
-                setItem(currentRow, 1, defaultItem(tr("%1 attachment(s) present", nullptr, attachments.size()).arg(attachments.size())));
+                setItem(currentRow, 1, defaultItem(tr("%1 attachment(s) present", nullptr, trQuandity(attachments.size())).arg(attachments.size())));
 
                 size_t number = 0;
                 for(const AbstractAttachment *attachment : attachments) {
@@ -524,7 +527,7 @@ void FileInfoModel::updateCache()
                 if(!editionEntries.empty()) {
                     auto *editionsItem = defaultItem(tr("Editions"));
                     setItem(++currentRow, editionsItem);
-                    setItem(currentRow, 1, defaultItem(tr("%1 edition(s) present", nullptr, editionEntries.size()).arg(editionEntries.size())));
+                    setItem(currentRow, 1, defaultItem(tr("%1 edition(s) present", nullptr, trQuandity(editionEntries.size())).arg(editionEntries.size())));
                     size_t editionNumber = 0;
                     for(const auto &edition : editionEntries) {
                         auto *editionItem = defaultItem(tr("Edition #%1").arg(++editionNumber));
@@ -554,7 +557,7 @@ void FileInfoModel::updateCache()
                 if(!chapters.empty()) {
                     auto *chaptersItem = defaultItem(tr("Chapters"));
                     setItem(++currentRow, chaptersItem);
-                    setItem(currentRow, 1, defaultItem(tr("%1 chapter(s) present", nullptr, chapters.size()).arg(chapters.size())));
+                    setItem(currentRow, 1, defaultItem(tr("%1 chapter(s) present", nullptr, trQuandity(chapters.size())).arg(chapters.size())));
                     for(const AbstractChapter *chapter : chapters) {
                         addChapter(chapter, chaptersItem);
                     }
@@ -592,18 +595,14 @@ void FileInfoModel::updateCache()
         }
 
         // notifications
-        auto currentNotifications = m_file->gatherRelatedNotifications();
-        if(!currentNotifications.empty()) {
-             auto *notificationsItem= defaultItem(m_originalNotifications ? tr("Notifications (reparsing after saving)") : tr("Notifications"));
-            addNotifications(&currentNotifications, notificationsItem);
-            setItem(++currentRow, notificationsItem);
+        auto *const diagItem = defaultItem(tr("Diagnostic messages"));
+        addDiagMessages(m_diag, diagItem);
+        setItem(++currentRow, diagItem);
+        if (m_diagReparsing) {
+            auto *diagReparsingItem = defaultItem(tr("Diagnostic messages from reparsing"));
+            addDiagMessages(m_diagReparsing, diagReparsingItem);
+            setItem(++currentRow, diagReparsingItem);
         }
-        if(m_originalNotifications && !m_originalNotifications->empty()) {
-            auto *notificationsItem = defaultItem(tr("Notifications"));
-            addNotifications(m_originalNotifications, notificationsItem);
-            setItem(++currentRow, notificationsItem);
-        }
-
     }
     endResetModel();
 }
diff --git a/gui/fileinfomodel.h b/gui/fileinfomodel.h
index 4bbf224..c4089ec 100644
--- a/gui/fileinfomodel.h
+++ b/gui/fileinfomodel.h
@@ -7,8 +7,7 @@
 
 namespace Media {
 class MediaFileInfo;
-class Notification;
-typedef std::list<Notification> NotificationList;
+class Diagnostics;
 }
 
 namespace QtGui {
@@ -17,12 +16,12 @@ class FileInfoModel : public QStandardItemModel
 {
     Q_OBJECT
 public:
-    explicit FileInfoModel(Media::MediaFileInfo *fileInfo = nullptr, QObject *parent = nullptr);
+    explicit FileInfoModel(QObject *parent = nullptr);
 
     QVariant headerData(int section, Qt::Orientation orientation, int role = Qt::DisplayRole) const;
 
     const Media::MediaFileInfo *fileInfo() const;
-    void setFileInfo(Media::MediaFileInfo *fileInfo, Media::NotificationList *originalNotifications = nullptr);
+    void setFileInfo(Media::MediaFileInfo &fileInfo, Media::Diagnostics &diag, Media::Diagnostics *diagReparsing = nullptr);
 
 #if defined(GUI_QTWIDGETS)
     static const QIcon &informationIcon();
@@ -36,7 +35,8 @@ private:
 
 private:
     Media::MediaFileInfo *m_file;
-    Media::NotificationList *m_originalNotifications;
+    Media::Diagnostics *m_diag;
+    Media::Diagnostics *m_diagReparsing;
 };
 
 }
diff --git a/gui/notificationmodel.cpp b/gui/notificationmodel.cpp
index 9b96e4a..8bd59e6 100644
--- a/gui/notificationmodel.cpp
+++ b/gui/notificationmodel.cpp
@@ -1,5 +1,7 @@
 #include "./notificationmodel.h"
 
+#include "../misc/utility.h"
+
 #include <c++utilities/chrono/datetime.h>
 
 #include <QApplication>
@@ -9,14 +11,15 @@
 using namespace std;
 using namespace ChronoUtilities;
 using namespace Media;
+using namespace Utility;
 
 namespace QtGui {
 
-NotificationModel::NotificationModel(QObject *parent) :
+DiagModel::DiagModel(QObject *parent) :
     QAbstractListModel(parent)
 {}
 
-QVariant NotificationModel::headerData(int section, Qt::Orientation orientation, int role) const
+QVariant DiagModel::headerData(int section, Qt::Orientation orientation, int role) const
 {
     switch(orientation) {
     case Qt::Horizontal:
@@ -41,7 +44,7 @@ QVariant NotificationModel::headerData(int section, Qt::Orientation orientation,
     return QVariant();
 }
 
-int NotificationModel::columnCount(const QModelIndex &parent) const
+int DiagModel::columnCount(const QModelIndex &parent) const
 {
     if(!parent.isValid()) {
         return 3;
@@ -49,27 +52,27 @@ int NotificationModel::columnCount(const QModelIndex &parent) const
     return 0;
 }
 
-int NotificationModel::rowCount(const QModelIndex &parent) const
+int DiagModel::rowCount(const QModelIndex &parent) const
 {
     if(!parent.isValid()) {
-        return m_notifications.size();
+        return sizeToInt(m_diag.size());
     }
     return 0;
 }
 
-Qt::ItemFlags NotificationModel::flags(const QModelIndex &index) const
+Qt::ItemFlags DiagModel::flags(const QModelIndex &index) const
 {
     return QAbstractListModel::flags(index);
 }
 
-QVariant NotificationModel::data(const QModelIndex &index, int role) const
+QVariant DiagModel::data(const QModelIndex &index, int role) const
 {
-    if(index.isValid() && index.row() < m_notifications.size()) {
+    if(index.isValid() && index.row() >= 0 && static_cast<std::size_t>(index.row()) < m_diag.size()) {
         switch(role) {
         case Qt::DisplayRole:
             switch(index.column()) {
             case 0: {
-                const string &context = m_notifications.at(index.row()).context();
+                const string &context = m_diag[static_cast<std::size_t>(index.row())].context();
                 if(context.empty()) {
                     return tr("unspecified");
                 } else {
@@ -77,9 +80,9 @@ QVariant NotificationModel::data(const QModelIndex &index, int role) const
                 }
             }
             case 1:
-                return QString::fromUtf8(m_notifications.at(index.row()).message().c_str());
+                return QString::fromUtf8(m_diag[static_cast<std::size_t>(index.row())].message().c_str());
             case 2:
-                return QString::fromUtf8(m_notifications.at(index.row()).creationTime().toString(DateTimeOutputFormat::DateAndTime, true).c_str());
+                return QString::fromUtf8(m_diag[static_cast<std::size_t>(index.row())].creationTime().toString(DateTimeOutputFormat::DateAndTime, true).c_str());
             default:
                 ;
             }
@@ -87,18 +90,19 @@ QVariant NotificationModel::data(const QModelIndex &index, int role) const
         case Qt::DecorationRole:
             switch(index.column()) {
             case 0:
-                switch(m_notifications.at(index.row()).type()) {
-                case NotificationType::Information:
-                    return informationIcon();
-                case NotificationType::Warning:
-                    return warningIcon();
-                case NotificationType::Critical:
-                    return errorIcon();
-                case NotificationType::Debug:
+                switch(m_diag[static_cast<std::size_t>(index.row())].level()) {
+                case DiagLevel::None:
+                case DiagLevel::Debug:
                     return debugIcon();
-                default:
-                    ;
+                case DiagLevel::Information:
+                    return informationIcon();
+                case DiagLevel::Warning:
+                    return warningIcon();
+                case DiagLevel::Critical:
+                case DiagLevel::Fatal:
+                    return errorIcon();
                 }
+                break;
             default:
                 ;
             }
@@ -110,42 +114,37 @@ QVariant NotificationModel::data(const QModelIndex &index, int role) const
     return QVariant();
 }
 
-const QList<Notification> &NotificationModel::notifications() const
+const Diagnostics &DiagModel::diagnostics() const
 {
-    return m_notifications;
+    return m_diag;
 }
 
-void NotificationModel::setNotifications(const QList<Notification> &notifications)
+void DiagModel::setDiagnostics(const Media::Diagnostics &notifications)
 {
     beginResetModel();
-    m_notifications = notifications;
+    m_diag = notifications;
     endResetModel();
 }
 
-void NotificationModel::setNotifications(const NotificationList &notifications)
-{
-    setNotifications(QList<Notification>::fromStdList(notifications));
-}
-
-const QIcon &NotificationModel::informationIcon()
+const QIcon &DiagModel::informationIcon()
 {
     static const QIcon icon = QApplication::style()->standardIcon(QStyle::SP_MessageBoxInformation);
     return icon;
 }
 
-const QIcon &NotificationModel::warningIcon()
+const QIcon &DiagModel::warningIcon()
 {
     static const QIcon icon = QApplication::style()->standardIcon(QStyle::SP_MessageBoxWarning);
     return icon;
 }
 
-const QIcon &NotificationModel::errorIcon()
+const QIcon &DiagModel::errorIcon()
 {
     static const QIcon icon = QApplication::style()->standardIcon(QStyle::SP_MessageBoxCritical);
     return icon;
 }
 
-const QIcon &NotificationModel::debugIcon()
+const QIcon &DiagModel::debugIcon()
 {
     static const QIcon icon = QIcon(QStringLiteral("/images/bug"));
     return icon;
diff --git a/gui/notificationmodel.h b/gui/notificationmodel.h
index 2caecf0..05d4b54 100644
--- a/gui/notificationmodel.h
+++ b/gui/notificationmodel.h
@@ -1,17 +1,17 @@
 #ifndef NOTIFICATIONMODEL_H
 #define NOTIFICATIONMODEL_H
 
-#include <tagparser/notification.h>
+#include <tagparser/diagnostics.h>
 
 #include <QAbstractListModel>
 
 namespace QtGui {
 
-class NotificationModel : public QAbstractListModel
+class DiagModel : public QAbstractListModel
 {
     Q_OBJECT
 public:
-    explicit NotificationModel(QObject *parent = nullptr);
+    explicit DiagModel(QObject *parent = nullptr);
 
     QVariant headerData(int section, Qt::Orientation orientation, int role = Qt::DisplayRole) const;
     int columnCount(const QModelIndex &parent) const;
@@ -19,9 +19,8 @@ public:
     Qt::ItemFlags flags(const QModelIndex &index) const;
     QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const;
 
-    const QList<Media::Notification> &notifications() const;
-    void setNotifications(const QList<Media::Notification> &notifications);
-    void setNotifications(const Media::NotificationList &notifications);
+    const Media::Diagnostics &diagnostics() const;
+    void setDiagnostics(const Media::Diagnostics &diagnostics);
 
     static const QIcon &informationIcon();
     static const QIcon &warningIcon();
@@ -33,7 +32,7 @@ signals:
 public slots:
 
 private:
-    QList<Media::Notification> m_notifications;
+    Media::Diagnostics m_diag;
 
 };
 
diff --git a/gui/picturepreviewselection.cpp b/gui/picturepreviewselection.cpp
index 68de3ab..7f5892e 100644
--- a/gui/picturepreviewselection.cpp
+++ b/gui/picturepreviewselection.cpp
@@ -11,6 +11,7 @@
 #include <tagparser/id3/id3v2frame.h>
 #include <tagparser/vorbis/vorbiscomment.h>
 #include <tagparser/vorbis/vorbiscommentfield.h>
+#include <tagparser/diagnostics.h>
 
 #include <qtutilities/misc/conversion.h>
 
@@ -318,8 +319,10 @@ void PicturePreviewSelection::addOfSelectedType(const QString &path)
     TagValue &selectedCover = m_values[m_currentTypeIndex];
     try {
         MediaFileInfo fileInfo(toNativeFileName(path).constData());
+        Diagnostics diag;
         fileInfo.open(true);
-        fileInfo.parseContainerFormat();
+        fileInfo.parseContainerFormat(diag);
+        // TODO: show diagnostic messages
         auto mimeType = QString::fromUtf8(fileInfo.mimeType());
         bool ok;
         mimeType = QInputDialog::getText(this, tr("Enter/confirm mime type"), tr("Confirm or enter the mime type of the selected file."), QLineEdit::Normal, mimeType, &ok);
diff --git a/gui/tageditorwidget.cpp b/gui/tageditorwidget.cpp
index 968309c..bb416bb 100644
--- a/gui/tageditorwidget.cpp
+++ b/gui/tageditorwidget.cpp
@@ -164,7 +164,7 @@ TagEditorWidget::~TagEditorWidget()
 const QByteArray &TagEditorWidget::generateFileInfoHtml()
 {
     if(m_fileInfoHtml.isEmpty()) {
-        m_fileInfoHtml = HtmlInfo::generateInfo(m_fileInfo, m_originalNotifications);
+        m_fileInfoHtml = HtmlInfo::generateInfo(m_fileInfo, m_diag, m_diagReparsing);
     }
     return m_fileInfoHtml;
 }
@@ -627,7 +627,8 @@ void TagEditorWidget::initInfoView()
             m_ui->tagSplitter->addWidget(m_infoTreeView);
         }
         if(!m_infoModel) {
-            m_infoModel = new FileInfoModel(m_fileInfo.isOpen() ? &m_fileInfo : nullptr, this);
+            m_infoModel = new FileInfoModel(this);
+            m_infoModel->setFileInfo(m_fileInfo, m_diag, m_makingResultsAvailable ? &m_diagReparsing : nullptr);
             m_infoTreeView->setModel(m_infoModel);
             m_infoTreeView->setHeaderHidden(true);
             m_infoTreeView->header()->setSectionResizeMode(QHeaderView::ResizeToContents);
@@ -658,7 +659,7 @@ void TagEditorWidget::updateInfoView()
 
     // update info model if present
     if(m_infoModel) {
-        m_infoModel->setFileInfo(m_fileInfo.isOpen() ? &m_fileInfo : nullptr); // resets the model
+        m_infoModel->setFileInfo(m_fileInfo, m_diag, m_makingResultsAvailable ? &m_diagReparsing : nullptr); // resets the model
     }
 }
 
@@ -758,8 +759,6 @@ bool TagEditorWidget::startParsing(const QString &path, bool forceRefresh)
     // clear previous results and status
     m_tags.clear();
     m_fileInfo.clearParsingResults();
-    m_fileInfo.invalidateStatus();
-    m_fileInfo.invalidateNotifications();
     if(!sameFile) {
         // close last file if possibly open
         m_fileInfo.close();
@@ -768,25 +767,26 @@ bool TagEditorWidget::startParsing(const QString &path, bool forceRefresh)
         m_fileInfo.setSaveFilePath(string());
         m_fileInfo.setPath(toNativeFileName(path).data());
         // update file name and directory
-        QFileInfo fileInfo(path);
+        const QFileInfo fileInfo(path);
         m_lastDir = m_currentDir;
         m_currentDir = fileInfo.absolutePath();
         m_fileName = fileInfo.fileName();
     }
-    // update availability of making results
+    // write diagnostics to m_diagReparsing if making results are avalable
     m_makingResultsAvailable &= sameFile;
-    if(!m_makingResultsAvailable) {
-        m_originalNotifications.clear();
-    }
+    Diagnostics &diag = m_makingResultsAvailable ? m_diagReparsing : m_diag;
+    // clear diagnostics
+    diag.clear();
+    m_diagReparsing.clear();
     // show filename
     m_ui->fileNameLabel->setText(m_fileName);
     // define function to parse the file
-    auto startThread = [this] {
+    const auto startThread = [this, &diag] {
         char result;
         try { // credits for this nesting go to GCC regression 66145
             try {
+                // try to open with write access
                 try {
-                    // try to open with write access
                     m_fileInfo.reopen(false);
                 } catch(...) {
                     ::IoUtilities::catchIoFailure();
@@ -794,7 +794,7 @@ bool TagEditorWidget::startParsing(const QString &path, bool forceRefresh)
                     m_fileInfo.reopen(true);
                 }
                 m_fileInfo.setForceFullParse(Settings::values().editor.forceFullParse);
-                m_fileInfo.parseEverything();
+                m_fileInfo.parseEverything(diag);
                 result = ParsingSuccessful;
             } catch(const Failure &) {
                 // the file has been opened; parsing notifications will be shown in the info box
@@ -806,21 +806,19 @@ bool TagEditorWidget::startParsing(const QString &path, bool forceRefresh)
                 result = IoError;
             }
         } catch(const exception &e) {
-            m_fileInfo.addNotification(Media::NotificationType::Critical, string("Something completely unexpected happened: ") + e.what(), "parsing");
+            diag.emplace_back(Media::DiagLevel::Critical, argsToString("Something completely unexpected happened: ", + e.what()), "parsing");
             result = FatalParsingError;
         } catch(...) {
-            m_fileInfo.addNotification(Media::NotificationType::Critical, "Something completely unexpected happened", "parsing");
+            diag.emplace_back(Media::DiagLevel::Critical, "Something completely unexpected happened", "parsing");
             result = FatalParsingError;
         }
-        m_fileInfo.unregisterAllCallbacks();
         QMetaObject::invokeMethod(this, "showFile", Qt::QueuedConnection, Q_ARG(char, result));
     };
-    m_fileInfo.unregisterAllCallbacks();
     m_fileOperationOngoing = true;
     // perform the operation concurrently
     QtConcurrent::run(startThread);
     // inform user
-    static const QString statusMsg(tr("The file is beeing parsed ..."));
+    static const auto statusMsg(tr("The file is beeing parsed ..."));
     m_ui->parsingNotificationWidget->setNotificationType(NotificationType::Progress);
     m_ui->parsingNotificationWidget->setText(statusMsg);
     m_ui->parsingNotificationWidget->setVisible(true); // ensure widget is visible!
@@ -899,10 +897,13 @@ void TagEditorWidget::showFile(char result)
         }
 
         // show parsing status/result using parsing notification widget
-        auto worstNotificationType = m_fileInfo.worstNotificationTypeIncludingRelatedObjects();
-        if(worstNotificationType >= Media::NotificationType::Critical) {
-            // we catched no exception, but there are critical notifications
-            // -> treat critical notifications as fatal parsing errors
+        auto diagLevel = m_diag.level();
+        if (diagLevel < worstDiagLevel) {
+            diagLevel |= m_diagReparsing.level();
+        }
+        if(diagLevel >= DiagLevel::Critical) {
+            // we catched no exception, but there are critical diag messages
+            // -> treat those as fatal parsing errors
             result = LoadingResult::FatalParsingError;
         }
         switch(result) {
@@ -915,12 +916,12 @@ void TagEditorWidget::showFile(char result)
             m_ui->parsingNotificationWidget->setText(tr("File couldn't be parsed correctly."));
         }
         bool multipleSegmentsNotTested = m_fileInfo.containerFormat() == ContainerFormat::Matroska && m_fileInfo.container()->segmentCount() > 1;
-        if(worstNotificationType >= Media::NotificationType::Critical) {
+        if(diagLevel >= Media::DiagLevel::Critical) {
             m_ui->parsingNotificationWidget->setNotificationType(NotificationType::Critical);
-            m_ui->parsingNotificationWidget->appendLine(tr("There are critical parsing notifications."));
-        } else if(worstNotificationType == Media::NotificationType::Warning || m_fileInfo.isReadOnly() || !m_fileInfo.areTagsSupported() || multipleSegmentsNotTested) {
+            m_ui->parsingNotificationWidget->appendLine(tr("Errors occured."));
+        } else if(diagLevel == Media::DiagLevel::Warning || m_fileInfo.isReadOnly() || !m_fileInfo.areTagsSupported() || multipleSegmentsNotTested) {
             m_ui->parsingNotificationWidget->setNotificationType(NotificationType::Warning);
-            if(worstNotificationType == Media::NotificationType::Warning) {
+            if(diagLevel == Media::DiagLevel::Warning) {
                 m_ui->parsingNotificationWidget->appendLine(tr("There are warnings."));
             }
         }
@@ -1099,21 +1100,26 @@ bool TagEditorWidget::startSaving()
     m_fileInfo.setMinPadding(settings.minPadding);
     m_fileInfo.setMaxPadding(settings.maxPadding);
     m_fileInfo.setPreferredPadding(settings.preferredPadding);
-    // define functions to show the saving progress and to actually applying the changes
-    auto showProgress = [this] (StatusProvider &sender) -> void {
-        QMetaObject::invokeMethod(m_ui->makingNotificationWidget, "setPercentage", Qt::QueuedConnection, Q_ARG(int, static_cast<int>(sender.currentPercentage() * 100.0)));
-        if(m_abortClicked) {
-            QMetaObject::invokeMethod(m_ui->makingNotificationWidget, "setText", Qt::QueuedConnection, Q_ARG(QString, tr("Cancelling ...")));
-            m_fileInfo.tryToAbort();
-        } else {
-            QMetaObject::invokeMethod(m_ui->makingNotificationWidget, "setText", Qt::QueuedConnection, Q_ARG(QString, QString::fromStdString(sender.currentStatus())));
-        }
-    };
-    auto startThread = [this] {
+    const auto startThread = [this] {
+        // define functions to show the saving progress and to actually applying the changes
+        const auto showPercentage([this] (const AbortableProgressFeedback &progress) {
+            QMetaObject::invokeMethod(m_ui->makingNotificationWidget, "setPercentage", Qt::QueuedConnection, Q_ARG(int, progress.stepPercentage()));
+        });
+        const auto showStep([this] (AbortableProgressFeedback &progress) {
+            QMetaObject::invokeMethod(m_ui->makingNotificationWidget, "setPercentage", Qt::QueuedConnection, Q_ARG(int, progress.stepPercentage()));
+            if(m_abortClicked) {
+                progress.tryToAbort();
+                QMetaObject::invokeMethod(m_ui->makingNotificationWidget, "setText", Qt::QueuedConnection, Q_ARG(QString, tr("Cancelling ...")));
+            } else {
+                QMetaObject::invokeMethod(m_ui->makingNotificationWidget, "setText", Qt::QueuedConnection, Q_ARG(QString, QString::fromStdString(progress.step())));
+            }
+        });
+        AbortableProgressFeedback progress(std::move(showStep), std::move(showPercentage));
+
         bool processingError = false, ioError = false;
         try {
             try {
-                m_fileInfo.applyChanges();
+                m_fileInfo.applyChanges(m_diag, progress);
             } catch(const Failure &) {
                 processingError = true;
             } catch(...) {
@@ -1121,17 +1127,14 @@ bool TagEditorWidget::startSaving()
                 ioError = true;
             }
         } catch(const exception &e) {
-            m_fileInfo.addNotification(Media::NotificationType::Critical, string("Something completely unexpected happened: ") + e.what(), "making");
+            m_diag.emplace_back(Media::DiagLevel::Critical, argsToString("Something completely unexpected happened: ", e.what()), "making");
             processingError = true;
         } catch(...) {
-            m_fileInfo.addNotification(Media::NotificationType::Critical, "Something completely unexpected happened", "making");
+            m_diag.emplace_back(Media::DiagLevel::Critical, "Something completely unexpected happened", "making");
             processingError = true;
         }
-        m_fileInfo.unregisterAllCallbacks();
         QMetaObject::invokeMethod(this, "showSavingResult", Qt::QueuedConnection, Q_ARG(bool, processingError), Q_ARG(bool, ioError));
     };
-    m_fileInfo.unregisterAllCallbacks();
-    m_fileInfo.registerCallback(showProgress);
     m_fileOperationOngoing = true;
     // use another thread to perform the operation
     QtConcurrent::run(startThread);
@@ -1155,17 +1158,17 @@ void TagEditorWidget::showSavingResult(bool processingError, bool ioError)
     m_ui->makingNotificationWidget->setPercentage(-1);
     m_ui->makingNotificationWidget->setHidden(false);
     m_makingResultsAvailable = true;
-    m_originalNotifications = m_fileInfo.gatherRelatedNotifications();
     if(!processingError && !ioError) {
         // display status messages
         QString statusMsg;
         size_t critical = 0, warnings = 0;
-        for(const Notification &notification : m_originalNotifications) {
-            switch(notification.type()) {
-            case Media::NotificationType::Critical:
+        for(const auto &msg : m_diag) {
+            switch(msg.level()) {
+            case Media::DiagLevel::Fatal:
+            case Media::DiagLevel::Critical:
                 ++critical;
                 break;
-            case Media::NotificationType::Warning:
+            case Media::DiagLevel::Warning:
                 ++warnings;
                 break;
             default:
@@ -1174,12 +1177,12 @@ void TagEditorWidget::showSavingResult(bool processingError, bool ioError)
         }
         if(warnings || critical) {
             if(critical) {
-                statusMsg = tr("The tags have been saved, but there is/are %1 warning(s) ", 0, warnings).arg(warnings);
-                statusMsg.append(tr("and %1 error(s).", 0, critical).arg(critical));
+                statusMsg = tr("The tags have been saved, but there is/are %1 warning(s) ", nullptr, trQuandity(warnings)).arg(warnings);
+                statusMsg.append(tr("and %1 error(s).", nullptr, trQuandity(critical)).arg(critical));
             } else {
-                statusMsg = tr("The tags have been saved, but there is/are %1 warning(s).", 0, warnings).arg(warnings);
+                statusMsg = tr("The tags have been saved, but there is/are %1 warning(s).", nullptr, trQuandity(warnings)).arg(warnings);
             }
-            m_ui->makingNotificationWidget->setNotificationType(critical > 0 ? NotificationType::Critical : NotificationType::Warning);
+            m_ui->makingNotificationWidget->setNotificationType(critical ? NotificationType::Critical : NotificationType::Warning);
 
         } else {
             statusMsg = tr("The tags have been saved.");
diff --git a/gui/tageditorwidget.h b/gui/tageditorwidget.h
index dae9a06..423e097 100644
--- a/gui/tageditorwidget.h
+++ b/gui/tageditorwidget.h
@@ -5,6 +5,7 @@
 #include "./webviewdefs.h"
 
 #include <tagparser/mediafileinfo.h>
+#include <tagparser/diagnostics.h>
 
 #include <QWidget>
 #include <QByteArray>
@@ -49,7 +50,7 @@ public:
     const QString &currentPath() const;
     const QString &currentDir() const;
     Media::MediaFileInfo &fileInfo();
-    Media::NotificationList &originalNotifications();
+    const Media::Diagnostics &diagnostics() const;
     bool isTagEditShown() const;
     const QByteArray &fileInfoHtml() const;
     const QByteArray &generateFileInfoHtml();
@@ -150,9 +151,10 @@ private:
     QString m_lastDir;
     QString m_saveFilePath;
     // status
+    Media::Diagnostics m_diag;
+    Media::Diagnostics m_diagReparsing;
     bool m_nextFileAfterSaving;
     bool m_makingResultsAvailable;
-    Media::NotificationList m_originalNotifications;
     bool m_abortClicked;
     bool m_fileOperationOngoing;
 };
@@ -191,11 +193,11 @@ inline Media::MediaFileInfo &TagEditorWidget::fileInfo()
 }
 
 /*!
- * \brief Returns the original notifications.
+ * \brief Returns the diagnostic messages.
  */
-inline Media::NotificationList &TagEditorWidget::originalNotifications()
+inline const Media::Diagnostics &TagEditorWidget::diagnostics() const
 {
-    return m_originalNotifications;
+    return m_diag;
 }
 
 /*!
diff --git a/misc/htmlinfo.cpp b/misc/htmlinfo.cpp
index c153891..182896f 100644
--- a/misc/htmlinfo.cpp
+++ b/misc/htmlinfo.cpp
@@ -9,7 +9,6 @@
 #include <tagparser/mp4/mp4container.h>
 #include <tagparser/abstracttrack.h>
 #include <tagparser/abstractattachment.h>
-#include <tagparser/notification.h>
 
 #include <qtutilities/resources/resources.h>
 
@@ -56,6 +55,7 @@ using namespace std;
 using namespace ConversionUtilities;
 using namespace ChronoUtilities;
 using namespace Media;
+using namespace Utility;
 
 namespace HtmlInfo {
 
@@ -308,11 +308,12 @@ class Generator
 {
 public:
 
-    Generator(const MediaFileInfo &file, NotificationList &originalNotifications) :
+    Generator(const MediaFileInfo &file, Diagnostics &diag, Diagnostics &diagReparsing) :
         m_writer(&m_res),
         m_rowMaker(m_writer),
         m_file(file),
-        originalNotifications(originalNotifications)
+        m_diag(diag),
+        m_diagReparsing(diagReparsing)
     {}
 
     QString mkStyle()
@@ -808,33 +809,33 @@ public:
         }
     }
 
-    void mkNotifications(NotificationList &notifications, bool reparsing = false)
+    void mkNotifications(Diagnostics &diag, bool reparsing = false)
     {
-        if(notifications.size()) {
-            startTableSection();
-            const QString moreId(reparsing ? QStringLiteral("notificationsReparsingMore") : QStringLiteral("notificationsMore"));
-            m_rowMaker.startRow(reparsing ? QCoreApplication::translate("HtmlInfo", "Notifications (reparsing after saving)") : QCoreApplication::translate("HtmlInfo", "Notifications"));
-            m_writer.writeCharacters(QCoreApplication::translate("HtmlInfo", "%1 notification(s) available", 0, static_cast<int>(notifications.size())).arg(notifications.size()));
-            mkSpace();
-            mkDetailsLink(moreId, QCoreApplication::translate("HtmlInfo", "show notifications"));
-            m_rowMaker.endRow();
-            m_writer.writeEndElement();
+        if (diag.empty()) {
+            return;
+        }
+        startTableSection();
+        const QString moreId(reparsing ? QStringLiteral("notificationsReparsingMore") : QStringLiteral("notificationsMore"));
+        m_rowMaker.startRow(reparsing ? QCoreApplication::translate("HtmlInfo", "Notifications (reparsing after saving)") : QCoreApplication::translate("HtmlInfo", "Notifications"));
+        m_writer.writeCharacters(QCoreApplication::translate("HtmlInfo", "%1 notification(s) available", nullptr, trQuandity(diag.size())).arg(diag.size()));
+        mkSpace();
+        mkDetailsLink(moreId, QCoreApplication::translate("HtmlInfo", "show notifications"));
+        m_rowMaker.endRow();
+        m_writer.writeEndElement();
 
-            startExtendedTableSection(moreId);
-            m_rowMaker.startHorizontalSubTab(QString(), QStringList() << QString() << QCoreApplication::translate("HtmlInfo", "Context") << QCoreApplication::translate("HtmlInfo", "Message") << QCoreApplication::translate("HtmlInfo", "Time"));
-            Notification::sortByTime(notifications);
-            for(const Notification &notification : notifications) {
-                m_writer.writeStartElement(QStringLiteral("tr"));
-                m_writer.writeEmptyElement(QStringLiteral("td"));
-                m_writer.writeAttribute(QStringLiteral("class"), qstr(notification.typeName()));
-                m_writer.writeTextElement(QStringLiteral("td"), qstr(notification.context()));
-                m_writer.writeTextElement(QStringLiteral("td"), qstr(notification.message()));
-                m_writer.writeTextElement(QStringLiteral("td"), qstr(notification.creationTime().toString(DateTimeOutputFormat::DateAndTime, false)));
-                m_writer.writeEndElement();
-            }
-            m_rowMaker.endSubTab();
+        startExtendedTableSection(moreId);
+        m_rowMaker.startHorizontalSubTab(QString(), QStringList({QString(), QCoreApplication::translate("HtmlInfo", "Context"), QCoreApplication::translate("HtmlInfo", "Message"), QCoreApplication::translate("HtmlInfo", "Time")}));
+        for(const auto &msg : diag) {
+            m_writer.writeStartElement(QStringLiteral("tr"));
+            m_writer.writeEmptyElement(QStringLiteral("td"));
+            m_writer.writeAttribute(QStringLiteral("class"), qstr(msg.levelName()));
+            m_writer.writeTextElement(QStringLiteral("td"), qstr(msg.context()));
+            m_writer.writeTextElement(QStringLiteral("td"), qstr(msg.message()));
+            m_writer.writeTextElement(QStringLiteral("td"), qstr(msg.creationTime().toString(DateTimeOutputFormat::DateAndTime, false)));
             m_writer.writeEndElement();
         }
+        m_rowMaker.endSubTab();
+        m_writer.writeEndElement();
     }
 
     void mkDoc()
@@ -932,8 +933,8 @@ public:
             if(m_file.paddingSize()) {
                 rowMaker.mkRow(QCoreApplication::translate("HtmlInfo", "Padding size"), QStringLiteral("%1 (%2 %)").arg(qstr(dataSizeToString(m_file.paddingSize(), true))).arg(static_cast<double>(m_file.paddingSize()) / m_file.size() * 100.0, 0, 'g', 2));
             }
-            rowMaker.mkRow(QCoreApplication::translate("HtmlInfo", "Tag position"), container->determineTagPosition());
-            rowMaker.mkRow(QCoreApplication::translate("HtmlInfo", "Index position"), container->determineIndexPosition());
+            rowMaker.mkRow(QCoreApplication::translate("HtmlInfo", "Tag position"), container->determineTagPosition(m_diagReparsing));
+            rowMaker.mkRow(QCoreApplication::translate("HtmlInfo", "Index position"), container->determineIndexPosition(m_diagReparsing));
 
             m_writer.writeEndElement();
         }
@@ -1110,11 +1111,8 @@ public:
         }
 
         // notifications
-        auto currentNotifications = m_file.gatherRelatedNotifications();
-        mkNotifications(currentNotifications, !originalNotifications.empty());
-        if(!originalNotifications.empty()) {
-            mkNotifications(originalNotifications);
-        }
+        mkNotifications(m_diag);
+        mkNotifications(m_diagReparsing, true);
 
         // </table> </body> </html>
 
@@ -1132,7 +1130,8 @@ private:
     QByteArray m_res;
     RowMaker m_rowMaker;
     const MediaFileInfo &m_file;
-    NotificationList &originalNotifications;
+    Diagnostics &m_diag;
+    Diagnostics &m_diagReparsing;
 };
 
 /*!
@@ -1143,9 +1142,9 @@ private:
  * A QGuiApplication instance should be available for setting fonts.
  * A QApplication instance should be available for standard icons.
  */
-QByteArray generateInfo(const MediaFileInfo &file, NotificationList &originalNotifications)
+QByteArray generateInfo(const MediaFileInfo &file, Diagnostics &diag, Diagnostics &diagReparsing)
 {
-    Generator gen(file, originalNotifications);
+    Generator gen(file, diag, diagReparsing);
     gen.mkDoc();
 #ifdef QT_DEBUG
     QFile test(QStringLiteral("/tmp/test.xhtml"));
diff --git a/misc/htmlinfo.h b/misc/htmlinfo.h
index 0daffb4..e972c89 100644
--- a/misc/htmlinfo.h
+++ b/misc/htmlinfo.h
@@ -7,13 +7,12 @@
 
 namespace Media {
 class MediaFileInfo;
-class Notification;
-typedef std::list<Notification> NotificationList;
+class Diagnostics;
 }
 
 namespace HtmlInfo {
 
-QByteArray generateInfo(const Media::MediaFileInfo &file, Media::NotificationList &originalNotifications);
+QByteArray generateInfo(const Media::MediaFileInfo &file, Media::Diagnostics &diag, Media::Diagnostics &diagReparsing);
 
 }
 
diff --git a/misc/utility.h b/misc/utility.h
index d906dd7..aed01e4 100644
--- a/misc/utility.h
+++ b/misc/utility.h
@@ -30,6 +30,16 @@ void parseFileName(const QString &fileName, QString &title, int &trackNumber);
 QString printModel(QAbstractItemModel *model);
 void printModelIndex(const QModelIndex &index, QString &res, int level);
 
+constexpr int sizeToInt(std::size_t size)
+{
+    return size > std::numeric_limits<int>::max() ? std::numeric_limits<int>::max() : static_cast<int>(size);
+}
+
+constexpr int trQuandity(quint64 quandity)
+{
+    return quandity > std::numeric_limits<int>::max() ? std::numeric_limits<int>::max() : static_cast<int>(quandity);
+}
+
 }
 
 #endif // UTILITYFEATURES_H
diff --git a/renamingutility/tageditorobject.cpp b/renamingutility/tageditorobject.cpp
index 9fa1720..50535d3 100644
--- a/renamingutility/tageditorobject.cpp
+++ b/renamingutility/tageditorobject.cpp
@@ -29,17 +29,17 @@ using namespace std;
 namespace RenamingUtility {
 
 /// \brief Adds notifications from \a statusProvider to \a notificationsObject.
-TAGEDITOR_JS_VALUE &operator <<(TAGEDITOR_JS_VALUE &notificationsObject, const StatusProvider &statusProvider)
+TAGEDITOR_JS_VALUE &operator <<(TAGEDITOR_JS_VALUE &diagObject, const Diagnostics &diag)
 {
     quint32 counter = 0;
-    for(const auto &notification : statusProvider.notifications()) {
+    for(const auto &msg : diag) {
         TAGEDITOR_JS_VALUE val;
-        val.setProperty("msg", QString::fromUtf8(notification.message().data()) TAGEDITOR_JS_READONLY);
-        val.setProperty("critical", notification.type() == NotificationType::Critical TAGEDITOR_JS_READONLY);
-        notificationsObject.setProperty(counter, val);
+        val.setProperty("msg", QString::fromUtf8(msg.message().data()) TAGEDITOR_JS_READONLY);
+        val.setProperty("critical", msg.level() >= DiagLevel::Critical TAGEDITOR_JS_READONLY);
+        diagObject.setProperty(counter, val);
         ++counter;
     }
-    return notificationsObject;
+    return diagObject;
 }
 
 /// \brief Add fields and notifications from \a tag to \a tagObject.
@@ -79,8 +79,6 @@ TAGEDITOR_JS_VALUE &operator <<(TAGEDITOR_JS_VALUE &tagObject, const Tag &tag)
     tagObject.setProperty("diskPos", pos.position() TAGEDITOR_JS_READONLY);
     tagObject.setProperty("diskTotal", pos.total() TAGEDITOR_JS_READONLY);
 
-    // add notifications
-    tagObject.setProperty("hasCriticalNotifications", tag.hasCriticalNotifications() TAGEDITOR_JS_READONLY);
     return tagObject;
 }
 
@@ -138,6 +136,7 @@ const QString &TagEditorObject::newRelativeDirectory() const
 
 TAGEDITOR_JS_VALUE TagEditorObject::parseFileInfo(const QString &fileName)
 {
+    Diagnostics diag;
     MediaFileInfo fileInfo(toNativeFileName(fileName).data());
 
     // add basic file information
@@ -153,7 +152,7 @@ TAGEDITOR_JS_VALUE TagEditorObject::parseFileInfo(const QString &fileName)
     // parse further file information
     bool criticalParseingErrorOccured = false;
     try {
-        fileInfo.parseEverything();
+        fileInfo.parseEverything(diag);
     } catch(const Failure &) {
         // parsing notifications will be addded anyways
         criticalParseingErrorOccured = true;
@@ -163,11 +162,11 @@ TAGEDITOR_JS_VALUE TagEditorObject::parseFileInfo(const QString &fileName)
     }
 
     // gather notifications
-    auto mainNotificationObject = m_engine->newArray(static_cast<uint>(fileInfo.notifications().size()));
-    mainNotificationObject << fileInfo;
-    criticalParseingErrorOccured |= fileInfo.hasCriticalNotifications();
-    fileInfoObject.setProperty(QStringLiteral("hasCriticalNotifications"), criticalParseingErrorOccured);
-    fileInfoObject.setProperty(QStringLiteral("notifications"), mainNotificationObject);
+    auto diagObj = m_engine->newArray(static_cast<uint>(diag.size()));
+    diagObj << diag;
+    criticalParseingErrorOccured |= diag.level() >= DiagLevel::Critical;
+    fileInfoObject.setProperty(QStringLiteral("hasCriticalMessages"), criticalParseingErrorOccured);
+    fileInfoObject.setProperty(QStringLiteral("diagMessages"), diagObj);
 
     // add MIME-type, suitable suffix and technical summary
     fileInfoObject.setProperty(QStringLiteral("mimeType"), QString::fromUtf8(fileInfo.mimeType()) TAGEDITOR_JS_READONLY);
@@ -186,9 +185,6 @@ TAGEDITOR_JS_VALUE TagEditorObject::parseFileInfo(const QString &fileName)
         combinedTagObject << tag;
         combinedTagNotifications << tag;
         tagObject << tag;
-        auto tagNotificationsObject = m_engine->newArray(static_cast<uint>(tag.notifications().size()));
-        tagNotificationsObject << tag;
-        tagObject.setProperty(QStringLiteral("notifications"), tagNotificationsObject TAGEDITOR_JS_READONLY);
         tagsObject.setProperty(tagIndex, tagObject TAGEDITOR_JS_READONLY);
     }
     combinedTagObject.setProperty(QStringLiteral("notifications"), combinedTagNotifications TAGEDITOR_JS_READONLY);
@@ -206,9 +202,6 @@ TAGEDITOR_JS_VALUE TagEditorObject::parseFileInfo(const QString &fileName)
         trackObject.setProperty(QStringLiteral("format"), QString::fromUtf8(track.formatName()));
         trackObject.setProperty(QStringLiteral("formatAbbreviation"), QString::fromUtf8(track.formatAbbreviation()));
         trackObject.setProperty(QStringLiteral("description"), QString::fromUtf8(track.description().data()));
-        auto trackNotificationsObject = m_engine->newArray(static_cast<uint>(track.notifications().size()));
-        trackNotificationsObject << track;
-        trackObject.setProperty(QStringLiteral("notifications"), trackNotificationsObject TAGEDITOR_JS_READONLY);
         tracksObject.setProperty(trackIndex, trackObject TAGEDITOR_JS_READONLY);
     }
 
@@ -228,12 +221,12 @@ TAGEDITOR_JS_VALUE TagEditorObject::parseFileName(const QString &fileName)
 
 TAGEDITOR_JS_VALUE TagEditorObject::allFiles(const QString &dirName)
 {
-    QDir dir(dirName);
+    const QDir dir(dirName);
     if(dir.exists()) {
-        QStringList files = dir.entryList(QDir::Files);
-        auto entriesObj = m_engine->newArray(files.length());
+        const auto files(dir.entryList(QDir::Files));
+        auto entriesObj = m_engine->newArray(static_cast<uint>(files.size()));
         quint32 counter = 0;
-        for(const QString &file : files) {
+        for(const auto &file : files) {
             entriesObj.setProperty(counter, file TAGEDITOR_JS_READONLY);
             ++counter;
         }
@@ -245,9 +238,9 @@ TAGEDITOR_JS_VALUE TagEditorObject::allFiles(const QString &dirName)
 
 TAGEDITOR_JS_VALUE TagEditorObject::firstFile(const QString &dirName)
 {
-    QDir dir(dirName);
+    const QDir dir(dirName);
     if(dir.exists()) {
-        QStringList files = dir.entryList(QDir::Files);
+        const auto files(dir.entryList(QDir::Files));
         if(!files.empty()) {
             return TAGEDITOR_JS_VALUE(files.first());
         }
diff --git a/tests/cli.cpp b/tests/cli.cpp
index fa05654..8ead2be 100644
--- a/tests/cli.cpp
+++ b/tests/cli.cpp
@@ -2,9 +2,27 @@
 #include <c++utilities/io/catchiofailure.h>
 #include <c++utilities/io/misc.h>
 #include <c++utilities/io/path.h>
-#include <c++utilities/tests/testutils.h>
+
+// order of includes and definition of operator << matters for C++ to resolve the correct overload
 
 #include <tagparser/mediafileinfo.h>
+#include <tagparser/diagnostics.h>
+
+namespace TestUtilities {
+
+/*!
+ * \brief Prints a DiagMessage to enable using it in CPPUNIT_ASSERT_EQUAL.
+ */
+inline std::ostream &operator <<(std::ostream &os, const Media::DiagMessage &diagMessage)
+{
+    return os << diagMessage.levelName() << ':' << ' ' << diagMessage.message() << ' ' << '(' << diagMessage.context() << ')';
+}
+
+}
+
+using namespace TestUtilities;
+
+#include <c++utilities/tests/testutils.h>
 
 #include <cppunit/extensions/HelperMacros.h>
 #include <cppunit/TestFixture.h>
@@ -804,9 +822,10 @@ void CliTests::testExtraction()
     // test extraction of cover
     const char *const args1[] = {"tageditor", "extract", "cover", "-f", mp4File1.data(), "-o", "/tmp/extracted.jpeg", nullptr};
     TESTUTILS_ASSERT_EXEC(args1);
+    Diagnostics diag;
     MediaFileInfo extractedInfo("/tmp/extracted.jpeg");
     extractedInfo.open(true);
-    extractedInfo.parseContainerFormat();
+    extractedInfo.parseContainerFormat(diag);
     CPPUNIT_ASSERT_EQUAL(22771_st, extractedInfo.size());
     CPPUNIT_ASSERT(ContainerFormat::Jpeg == extractedInfo.containerFormat());
     extractedInfo.invalidate();
@@ -819,12 +838,13 @@ void CliTests::testExtraction()
     CPPUNIT_ASSERT_EQUAL(0, remove("/tmp/extracted.jpeg"));
     TESTUTILS_ASSERT_EXEC(args3);
     extractedInfo.open(true);
-    extractedInfo.parseContainerFormat();
+    extractedInfo.parseContainerFormat(diag);
     CPPUNIT_ASSERT_EQUAL(22771_st, extractedInfo.size());
     CPPUNIT_ASSERT(ContainerFormat::Jpeg == extractedInfo.containerFormat());
     CPPUNIT_ASSERT_EQUAL(0, remove("/tmp/extracted.jpeg"));
     CPPUNIT_ASSERT_EQUAL(0, remove(mp4File2.data()));
     CPPUNIT_ASSERT_EQUAL(0, remove((mp4File2 + ".bak").data()));
+    CPPUNIT_ASSERT_EQUAL(Diagnostics(), diag);
 }
 
 /*!