Edit ID-Tag year tag isue with m4a files

[Spoon]

Re: Edit ID-Tag year tag isue with m4a files

Please upload the file to dropbox and provide a link.

[mwthreex]

I add tags to m4a file via exiftool:

exiftool -ItemList:year=1999 -Keys:year=1999 -Userdata:year=1999 file.m4a -overwrite_original

MediaInfo shows the year info like this:

Released date : 1999
yrrc : 1999
com.apple.quicktime.year : 1999

But Edit ID-Tag shows nothing:

https://i.imgur.com/9ABbeAX.jpg

What is the problem?