# \[F\] illegally large tag field created in m4a files: lost in itunes

**URL:** https://community.mp3tag.de/t/f-illegally-large-tag-field-created-in-m4a-files-lost-in-itunes/7943
**Category:** Fixed Bugs
**Tags:** bug-fixed
**Created:** [February 16, 2009, 8:48am UTC](https://community.mp3tag.de/t/f-illegally-large-tag-field-created-in-m4a-files-lost-in-itunes/7943 "2009-02-16T08:48:03Z")
**Posts on this page:** 1
**Showing post:** 1

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### Author: ![TechUser](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/t/c0e974/32.png) [@TechUser](https://community.mp3tag.de/u/TechUser)
#### Post date: [February 16, 2009, 8:48am UTC](https://community.mp3tag.de/t/f-illegally-large-tag-field-created-in-m4a-files-lost-in-itunes/7943/1 "2009-02-16T08:48:03Z")

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mp3tag allows one to create illegally large tags in m4a files (tested with Apple Lossless):  
illegal means any text field over 255 characters.

To recreate:  
add a comment field (%comment%) that exceeds 255 characters to an m4a file.  
It will not display in itunes (because it is illegal).

Add a comment field that is 255 chars or less.  
It will display in itunes.

(This may lead to worse problems, since one can't be sure that m4a readers will handle this problem gracefully, so should be corrected.)

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_[View the full topic](https://community.mp3tag.de/t/f-illegally-large-tag-field-created-in-m4a-files-lost-in-itunes/7943)._