# Updated Documentation — Work in Progress
**URL:** https://community.mp3tag.de/t/updated-documentation-work-in-progress/56547
**Category:** General Discussion
**Created:** [March 2, 2022, 12:57pm UTC](https://community.mp3tag.de/t/updated-documentation-work-in-progress/56547 "2022-03-02T12:57:59Z")
**Posts on this page:** 1
**Showing post:** 31
### Author:  [@ohrenkino](https://community.mp3tag.de/u/ohrenkino)
#### Post date: [March 6, 2022, 8:55am UTC](https://community.mp3tag.de/t/updated-documentation-work-in-progress/56547/31 "2022-03-06T08:55:30Z")
On the topic of filters
"It is not possible to filter by strings containing double quotations marks. This is a limitation of the feature." - I think that there was the workaround with $char(34)
e.g.
> [@Filter (Finding) double quotation marks "](https://community.mp3tag.de/t/filter-finding-double-quotation-marks/52685):
>
> Hi, Would there any filter argument that will find double quotation marks? I would like to change all nick names that have double quotation marks to single quotation marks but finding them all is the challenge. eg. from say "Slim" to 'Slim' or from "Guitar Shorty" to 'Guitar Shorty' etc Thanks
I am not sure if the filter syntax is really described correctly.
Most syntax examples start with
` ...`
(fascinatingly with some kind of metasyntax...)
but I think that this not really just a `` as there are filter examples like
> [@Filter expressions](https://community.mp3tag.de/t/filter-expressions/10080/3):
>
> Filter with Scripting Check if a field is longer than 4 characters: "$len(%bpm%)" GREATER 4 Files with multipe artist tags: "$meta\_sep(Artist,\\)" HAS \\ Check if two fields have the same value: "$if($eql(%artist%,%albumartist%),yes,no)" IS yes Check if the title is part of the filename: "$ifgreater($strstr(%\_filename%,%title%),0,yes,no)" IS yes
where the scripting part at the front is not really a ``
I would think that this is a "generating format string" enclosed in double quotation marks.
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