diff --git a/README.md b/README.md
index 59ab4e5..6522885 100644
--- a/README.md
+++ b/README.md
@@ -7,11 +7,19 @@ The tag editor can read and write the following tag formats:
 * iTunes-style MP4/M4A tags (MP4-DASH is supported)
 * ID3v1 and ID3v2 tags
     * conversion between ID3v1 and different versions of ID3v2 is possible
+    * mainly for use in MP3 files but can be added to any kind of file
 * Vorbis, Opus and FLAC comments in Ogg streams
     * cover art via "METADATA_BLOCK_PICTURE" is supported
 * Vorbis comments and "METADATA_BLOCK_PICTURE" in raw FLAC streams
 * Matroska/WebM tags and attachments
 
+Further remarks:
+
+* Unsupported file contents (such as unsupported tag formats) are *generally* preserved as-is.
+* Note that APE tags are *not* supported. APE tags in the beginning of a file are strongly
+  unrecommended and thus discarded when applying changes. APE tags at the end of the file
+  are preserved as-is when applying changes.
+
 ## Additional features
 The tag editor can also display technical information such as the ID, format,
 language, bitrate, duration, size, timestamps, sampling frequency, FPS and other information of the tracks.