# Modification of tags for mp4 and case conversion

**URL:** https://community.mp3tag.de/t/modification-of-tags-for-mp4-and-case-conversion/57644
**Category:** Support
**Created:** [June 15, 2022, 2:28pm UTC](https://community.mp3tag.de/t/modification-of-tags-for-mp4-and-case-conversion/57644 "2022-06-15T14:28:01Z")
**Posts on this page:** 6
**Page:** 1

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### Author: ![PLC](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/p/7ab992/32.png) [@PLC](https://community.mp3tag.de/u/PLC)
#### Post date: [June 15, 2022, 2:28pm UTC](https://community.mp3tag.de/t/modification-of-tags-for-mp4-and-case-conversion/57644/1 "2022-06-15T14:28:01Z")

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When I want to renew track on M4a music, renew track number with 0 first seems not working (for me)

Converting text like function proper in Excel (Example : I don't speak english --\> I Don't Speak English)

Could you help me ?

Thanks

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### Author: ![ohrenkino](https://community.mp3tag.de/user_avatar/community.mp3tag.de/ohrenkino/32/4843_2.png) [@ohrenkino](https://community.mp3tag.de/u/ohrenkino)
#### Post date: [June 15, 2022, 2:31pm UTC](https://community.mp3tag.de/t/modification-of-tags-for-mp4-and-case-conversion/57644/2 "2022-06-15T14:31:01Z")

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> [@PLC](#):
>
> M4a music, renew track number with 0 first seems not working

MP4 tags do not allow leading 0 in TRACK.

To convert the case, try an action of the type "Case Conversion"

> **[Case Conversion – Mp3tag Documentation](https://docs.mp3tag.de/actions/case-conversion/)**
>
> Documentation on the Case Conversion action type that can be performed as Quick Action or as reusable workflow from Action Groups. Mp3tag is the universal Tag Editor.

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### Author: ![PLC](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/p/7ab992/32.png) [@PLC](https://community.mp3tag.de/u/PLC)
#### Post date: [June 15, 2022, 2:34pm UTC](https://community.mp3tag.de/t/modification-of-tags-for-mp4-and-case-conversion/57644/3 "2022-06-15T14:34:48Z")

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Thanks for the quick response, but where can I found an example 🙂

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### Author: ![ohrenkino](https://community.mp3tag.de/user_avatar/community.mp3tag.de/ohrenkino/32/4843_2.png) [@ohrenkino](https://community.mp3tag.de/u/ohrenkino)
#### Post date: [June 15, 2022, 2:37pm UTC](https://community.mp3tag.de/t/modification-of-tags-for-mp4-and-case-conversion/57644/4 "2022-06-15T14:37:43Z")

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Here are the FAQS about how to create a new action - and the first example is about case conversion:

> [@Actions and batch-operations](https://community.mp3tag.de/t/actions-and-batch-operations/967):
>
> Mp3tag provides a variety of actions, which can be applied to filenames and tags. The actions are grouped together into named sets (action groups), which can be applied independently via Alt + 6. If you do not want to create a reusable action group for applying one single action, the Actions (Quick) toolbar button or keyboard shortcut Shift + Alt + 6 can be used. How to [create a new action](https://community.mp3tag.de/t/actions/967/2)? How to ... [change upper/lower case of tag fields or filenames](https://community.mp3tag.de/t/actions/967/3)? [replace the string “xyz” in tag-fields …](https://community.mp3tag.de/t/actions/967/4)

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### Author: ![PLC](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/p/7ab992/32.png) [@PLC](https://community.mp3tag.de/u/PLC)
#### Post date: [June 15, 2022, 2:43pm UTC](https://community.mp3tag.de/t/modification-of-tags-for-mp4-and-case-conversion/57644/5 "2022-06-15T14:43:37Z")

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Merci beaucoup.  
I'll try.

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### Author: ![system](https://community.mp3tag.de/uploads/default/original/2X/c/ce7035d426cb755a7916793326d23b465222a407.png) [@system](https://community.mp3tag.de/u/system)
#### Post date: [February 9, 2026, 12:29pm UTC](https://community.mp3tag.de/t/modification-of-tags-for-mp4-and-case-conversion/57644/6 "2026-02-09T12:29:48Z")

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