# renaming using "format value: filename" problem
**URL:** https://community.mp3tag.de/t/renaming-using-format-value-filename-problem/3355
**Category:** Support
**Created:** [May 24, 2006, 10:59am UTC](https://community.mp3tag.de/t/renaming-using-format-value-filename-problem/3355 "2006-05-24T10:59:48Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@shucks](https://community.mp3tag.de/u/shucks)
#### Post date: [May 24, 2006, 10:59am UTC](https://community.mp3tag.de/t/renaming-using-format-value-filename-problem/3355/1 "2006-05-24T10:59:48Z")
I'm doing a bit of tag standardization and renaming in one which makes it easier to fo the renaming part by a customized action, namely "reformat value: FILENAME". The problem with this is however that every time MP3TAG encounters a character in the TITLE tag (which goes into the new filename: "%track% %title%") which is considered invalid in a filename it simply reports this and ask if to proceed, unlike the tool 'rename by using tags' (or whatever it's called) which suggests an alternative filename. Any way to fix this?
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### Author:  [@Florian](https://community.mp3tag.de/u/Florian)
#### Post date: [May 26, 2006, 8:03pm UTC](https://community.mp3tag.de/t/renaming-using-format-value-filename-problem/3355/2 "2006-05-26T20:03:45Z")
Yeah, you can use the $validate function in your format string.
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### Author:  [@system](https://community.mp3tag.de/u/system)
#### Post date: [February 9, 2026, 12:19pm UTC](https://community.mp3tag.de/t/renaming-using-format-value-filename-problem/3355/3 "2026-02-09T12:19:45Z")