# Warning: hidden \\ in filename format string tag placeholders
**URL:** https://community.mp3tag.de/t/warning-hidden-in-filename-format-string-tag-placeholders/8944
**Category:** Support
**Created:** [September 13, 2009, 7:06pm UTC](https://community.mp3tag.de/t/warning-hidden-in-filename-format-string-tag-placeholders/8944 "2009-09-13T19:06:12Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@chrisjj](https://community.mp3tag.de/u/chrisjj)
#### Post date: [September 13, 2009, 7:06pm UTC](https://community.mp3tag.de/t/warning-hidden-in-filename-format-string-tag-placeholders/8944/1 "2009-09-13T19:06:12Z")
Anyone using format string tag placeholders in Tag-Filename or Export "Export file name" might like to know of this hazard. If you use a string
$validate(%band% ~ %album%.htm,\_)
(as I do to create an album info file in each album directory) and one of those tags values contains a \ character (unlikely but can happen), then that \ gets interpreted as a pathname element separator, creating a folder where one did not intend one. The fix is e.g.
$replace($validate(%band% ~ %album%.htm,_),,_)
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### Author:  [@system](https://community.mp3tag.de/u/system)
#### Post date: [February 9, 2026, 12:21pm UTC](https://community.mp3tag.de/t/warning-hidden-in-filename-format-string-tag-placeholders/8944/2 "2026-02-09T12:21:47Z")