# Undefined Latex commands

**URL:** <https://discourse.jabref.org/t/undefined-latex-commands/8984>\
**Category:** Help\
**Created:** [September 23, 2025, 1:56pm UTC](https://discourse.jabref.org/t/undefined-latex-commands/8984 "2025-09-23T13:56:18Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![JackW](https://avatars.discourse-cdn.com/v4/letter/j/67e7ee/32.png) [@JackW](https://discourse.jabref.org/u/JackW)\
**Post date:** [September 23, 2025, 1:56pm UTC](https://discourse.jabref.org/t/undefined-latex-commands/8984/1 "2025-09-23T13:56:18Z")

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Hi, I am shifting a reference library from Zotero to JabRef (exported library using the better bibtex plugin for Zotero) and tidying up issues.

I have managed to manually tidy up most issues in the bib file but using the "‘check integrity’ tool in JabRef I get a lot of messages with ‘LaTeX Warning: undefined command x’ where ‘x’ is predominantly LaTeX commands for non-English letters (e.g., \o or \c) and some others such as \textasciitilde.

Should JabRef recognise these commands and I am simply missing some setting somewhere or should all be replace with the ASCII/UTF-8 character?

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**Author:** ![Siedlerchr](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.jabref.org/siedlerchr/32/216_2.png) [@Siedlerchr](https://discourse.jabref.org/u/Siedlerchr)\
**Post date:** [September 23, 2025, 5:28pm UTC](https://discourse.jabref.org/t/undefined-latex-commands/8984/2 "2025-09-23T17:28:28Z")

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Hi,

This depends on your use case. If you use the old bibtex format then it’s probably wise to keep them. However, for the newer biblatex format, JabRef offers a conversion from Latex 2 Unicode so you don’t need to escape these characters. However, there might be cases where some comands cannot be translated or cannot be interpreted correctly

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<div class="post-metadata">

**Author:** ![JackW](https://avatars.discourse-cdn.com/v4/letter/j/67e7ee/32.png) [@JackW](https://discourse.jabref.org/u/JackW)\
**Post date:** [September 24, 2025, 7:00am UTC](https://discourse.jabref.org/t/undefined-latex-commands/8984/3 "2025-09-24T07:00:21Z")

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Setting biblatex as export format for better bibtex fixed all but one of the warnings. Thanks Christoph.