# Filename to Tag. Optional 3rd field possible?
**URL:** https://community.mp3tag.de/t/filename-to-tag-optional-3rd-field-possible/49844
**Category:** Support
**Created:** [August 6, 2020, 12:23pm UTC](https://community.mp3tag.de/t/filename-to-tag-optional-3rd-field-possible/49844 "2020-08-06T12:23:45Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@King\_John](https://community.mp3tag.de/u/King_John)
#### Post date: [August 6, 2020, 12:23pm UTC](https://community.mp3tag.de/t/filename-to-tag-optional-3rd-field-possible/49844/1 "2020-08-06T12:23:45Z")
Hi, my mp3 filenames are formatted with an optional third field. They would be either:
Artist A-Song B.mp3 or
Artist A-Song B-Remixed by C.mp3
Is there a way to make this third field optional when either using the Convert Filename to Tag or my own Custom Action? Using either the Convert or the Guess Values action seems to break if I don't have the third field (and second '-' deliminator.) My experimentation with square brackets has been unsuccessful - %artist%-%title%[-%track%]
Is the only way I can do this is to filter the files first into those two different formats and run separate Converts/Actions? Or is there a way of using '[' ']' optional brackets?
FYI. My goal is to move those three fields into Title, Artist and Track fields, then formatting the Title field to Title (Track) if the track field is populated, then remove the Track field.
Title : Song B (Remixed by C)
Artist : Artist A
Is there a better strategy to use? How would you do this?
Thank you in advance.
John..
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### Author:  [@LyricsLover](https://community.mp3tag.de/u/LyricsLover)
#### Post date: [August 6, 2020, 1:06pm UTC](https://community.mp3tag.de/t/filename-to-tag-optional-3rd-field-possible/49844/2 "2020-08-06T13:06:38Z")
> [@King\_John](#):
>
> Is there a way to make this third field optional when either using the Convert Filename to Tag
@ohrenkino wrote in his answer:
> [@Need help with advanced filename to tags](https://community.mp3tag.de/t/need-help-with-advanced-filename-to-tags/13359/4):
>
> Sorry - did I read something wrong? I thought we were talking about tag-filename. probably my mistake prior to the afternoon cup of coffee. Also apologies if I wasted your time - no, for the import of data you have to be exact. So there is no way around than to apply sensible filters and then extract the data with the appropriate mask.
Your strategy using filters seems to be the best way.
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### Author:  [@system](https://community.mp3tag.de/u/system)
#### Post date: [February 9, 2026, 12:28pm UTC](https://community.mp3tag.de/t/filename-to-tag-optional-3rd-field-possible/49844/3 "2026-02-09T12:28:45Z")