# Better way to share custom field mappings

**URL:** https://community.mp3tag.de/t/better-way-to-share-custom-field-mappings/53007
**Category:** General Discussion
**Created:** [April 29, 2021, 10:30am UTC](https://community.mp3tag.de/t/better-way-to-share-custom-field-mappings/53007 "2021-04-29T10:30:37Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![Crissov](https://community.mp3tag.de/user_avatar/community.mp3tag.de/crissov/32/6619_2.png) [@Crissov](https://community.mp3tag.de/u/Crissov)
#### Post date: [April 29, 2021, 10:30am UTC](https://community.mp3tag.de/t/better-way-to-share-custom-field-mappings/53007/1 "2021-04-29T10:30:37Z")

</div>

I've never used [custom tag field mappings](https://docs.mp3tag.de/customization/options/tags/mapping) much, but for [3GPP MP4 boxes and QT MOV atoms](https://community.mp3tag.de/t/mp4-felder-atom-box-in-anderer-software/48614/) I wanted to try it.

I then realized that they are exported as part of the binary `mp3tag.cfg`. I'd like to suggest to export (and import) them as a plain-text `.ini` file in the `/data` folder.

This way, one could also, for instance, share settings for _MediaMonkey_ users to support its custom tag fields:

| Tag Type | Target | Source |
| --- | --- | --- |
| MP4 | `rate` | `POPULARIMETER` |
| MP4 | `mood` | `MOOD` |
| MP4 | `isrc` | `ISRC` |
| MP4 | `lyrc` | `LYRICIST` |
| MP4 | `peop` | `INVOLVEDPEOPLE` |
| MP4 | `otit` | `ORIGTITLE` |
| MP4 | `oart` | `ORIGARTIST` |
| MP4 | `olyr` | `ORIGLYRICIST` |
| MP4 | `oday` | `ORIGYEAR` |
| MP4 | `empo` | `BPM` |
| MP4 | `publ` | `PUBLISHER` |

I would also like some explicit documentation on how Mp3tag stores custom MP4 fields (`TXXX;FOO` in ID3v2)): as `udta.----:FOO` or `udta.----:com.apple.iTunes:FOO`? ~~(Also see [this thread](https://community.mp3tag.de/t/suggestion-tag-field-mappings-mp4-clarification/10023) for the Mac version.)~~

Also related: [User-defined Field Mappings](https://community.mp3tag.de/t/user-defined-field-mappings/14614)