# Definition for \_FORMAT requires property variable as value

**URL:** https://community.mp3tag.de/t/definition-for-format-requires-property-variable-as-value/71947
**Category:** General Discussion
**Created:** [October 11, 2026, 8:42am UTC](https://community.mp3tag.de/t/definition-for-format-requires-property-variable-as-value/71947 "2026-10-11T08:42:14Z")
**Posts on this page:** 1
**Showing post:** 3

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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: [October 11, 2026, 9:36am UTC](https://community.mp3tag.de/t/definition-for-format-requires-property-variable-as-value/71947/3 "2026-10-11T09:36:58Z")

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Indeed, I did not think of the use-case to have a list of properties in 1 element - but that should be possible for read-only values.

I got my qualms with this thread

> [@Use placeholders in MP3tag to enter data in the tag fields](https://community.mp3tag.de/t/use-placeholders-in-mp3tag-to-enter-data-in-the-tag-fields/71940/):
>
> Hi. I've been using MP3tag for a long time and now I have a question. For use in a jukebox software I need to give my mp3s an album. I would like to use the artist name so all songs of an artist are grouped together in one 'album'. Is it possible to read in alle the files, then enter the placeholder %artist% in the album field, so that the files all get the specific artist name as album? I tried to simply put %artist% in the album field but then they all have %artist% as album....not the act…

in the back of my head where there was an attempt to set the value for a new field with the value from an old one.

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