# Question about the Tag Mapping page in the documentation
**URL:** https://community.mp3tag.de/t/question-about-the-tag-mapping-page-in-the-documentation/47559
**Category:** General Discussion
**Created:** [January 19, 2020, 1:12am UTC](https://community.mp3tag.de/t/question-about-the-tag-mapping-page-in-the-documentation/47559 "2020-01-19T01:12:20Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@phossler](https://community.mp3tag.de/u/phossler)
#### Post date: [January 19, 2020, 1:12am UTC](https://community.mp3tag.de/t/question-about-the-tag-mapping-page-in-the-documentation/47559/1 "2020-01-19T01:12:20Z")
> **[Tag Field Mappings – Mp3tag Documentation](https://docs.mp3tag.de/mapping/)**
>
> Overview of all available tag fields, their names in Mp3tag, and how they are mapped to the internal structures of the different tag formats. Mp3tag is the universal Tag Editor.
I use this page a lot as a reference
1. What do the "T = nn" mean in the Matroska column mean? Some have a field name but many are just T=30
Guess: Text field with nn characters max??
1. What do the 'ditto' marks mean in the ID3v2.4 column mean? Usually I've only ever seem 'ditto' used for the item above, never to the left
Guess: Same tag as the ID3v2.3 column??
I couldn't find any legend or interpretation on the page
If the page could be made a little clearer I think it'd help
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### Author:  [@dano](https://community.mp3tag.de/u/dano)
#### Post date: [January 19, 2020, 3:46pm UTC](https://community.mp3tag.de/t/question-about-the-tag-mapping-page-in-the-documentation/47559/2 "2020-01-19T15:46:13Z")
I guess if you read the matroska Tag Specifications on their site it should become clear. I'm not sure Mp3tag help file should explain a tagging spec.
The quotes refer to the ID3v2.3 column
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### Author:  [@phossler](https://community.mp3tag.de/u/phossler)
#### Post date: [January 19, 2020, 4:42pm UTC](https://community.mp3tag.de/t/question-about-the-tag-mapping-page-in-the-documentation/47559/3 "2020-01-19T16:42:46Z")
I don't think MP3Tag should explain MKV tagging specifications either
However, since that page is intended for the MP3Tag user to map MP3Tag fields for various types of files, I was suggesting that it might be a little more targeted or focused towards helping the user use MP3tag to map data to the correct destination field
For example.
1. Specifically using TALB in ID3.v2.4 instead of ditto to set the MP3Tag ALBUM field (formatting)
2. Using the MP3Tag ALBUM field to set the MKV TITLE (T50 IMHO doesn't add anything, but could be confusing [like to me])). Maybe adding a link to
[https://matroska.org/technical/specs/tagging/index.html](https://matroska.org/technical/specs/tagging/index.html)
or repeating some explanatory information??
1. What does MP3Tag field ALBUMARTISTSORT map to for MKV files? It just says T=30. Does that mean it will create a field called ALBUMARTISTSORT in the MKV file if it's not there?
Just my opinion