We support KaTeX.  (--katex)

I had a quick look at the page on gitlab-flavored markdoown.

Pandoc has extensions for
multiple underscores in words (+intraword_underscores)
URL auto-linking (+autolink_bare_uris)
Code and syntax highlighting (+backtick_code_blocks)

Not supported:

multiline blockquote
inline diff
special gitlab references
task lists
videos
special gitlab references
gitlab's special format for specifying math:
  $`x`$ inline
  ```math
  block
  ```

If you'd like, you can add an enhancement request to the
issue tracker for these features (please give the details
above).

But, part of me dies inside at the thought of supporting
yet another syntax for specifying math in Markdown (I thought
the three we already supported were enough!).


+++ Ognyan Moore [Oct 16 17 09:31 ]:
>   I have a feature request, to support [1]gitlab flavored markdown.  The
>   need in my case came from using gitlab at my academic institution, and
>   it I create pdfs of my markdown documents routinely.
>   Gitlab flavored markdown uses KaTeX for math, which I understand Pandoc
>   current does support.  The main issues I've noticed with pandoc/gitlab
>   flavored markdown compatibility has been with the use of math (although
>   there may be other issues I have not encountered).
>   Thanks,
>   Ogi
>
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>References
>
>   1. https://docs.gitlab.com/ee/user/markdown.html
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