# $regexp(%TITLE%,\[^0-9a-zA-Z\],) does not work

**URL:** https://community.mp3tag.de/t/regexp-title-0-9a-za-z-does-not-work/56445
**Category:** Mac
**Created:** [February 23, 2022, 11:02am UTC](https://community.mp3tag.de/t/regexp-title-0-9a-za-z-does-not-work/56445 "2022-02-23T11:02:33Z")
**Posts on this page:** 1
**Showing post:** 6

<div class="post-metadata">

### Author: ![Florian](https://community.mp3tag.de/user_avatar/community.mp3tag.de/florian/32/5759_2.png) [@Florian](https://community.mp3tag.de/u/Florian)
#### Post date: [March 2, 2022, 9:09am UTC](https://community.mp3tag.de/t/regexp-title-0-9a-za-z-does-not-work/56445/6 "2022-03-02T09:09:29Z")

</div>

The documentation on [Scripting Functions](https://community.mp3tag.de/t/scripting-functions/51689) states for `$regexp`:

> Please note that you have to escape comma and other special characters in expr.

So the most easiest way would be to just enclose the expression in ' (given that [and] are special characters in Mp3tag's [Format Strings and Available Placeholders](https://community.mp3tag.de/t/format-strings-and-available-placeholders/51688))

`$regexp(%TITLE%,'[^0-9a-zA-Z]',)`

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