What is the default markup language for .wiki pages?

I have read from the documentation at Wiki | GitLab that several markup extensions are supported. For instance, .wiki, .mediawiki, textile, etc.

I am new to GitLab and converting an old wiki to conform with the current conventions. Therefore, it would be useful to me to know what Wiki “language” is triggered when files have a .wiki extension.

I’ve been using WikiText in Eclipse so far to edit the pages that I’m converting but it seems like MediaText defaults to Textile. I vaguely remember that in the past, I was using a set of tools that defaulted .wiki files to MediaWiki.

Can I safely consider that GitLab also defaults to MediaWiki? Or is MediaWiki “activated” only for files with an explicit .mediawiki extension?

Yes, you can choose between Markdown, RDoc, AsciiDoc, or Org (whatever the latter may be).
In my installation of GitLab, I cannot choose mediawiki but maybe there are addons to support it.

The main problem is that GitLab is biased as it always chooses Markdown by default.
I do not know why all these platforms always use Markdown as first class citizen and have this bias (github is more flexible but in issues it also only supports Markdown syntax).
I have been using all formats and my favorite is AsciiDoc for sure. Already the Markdown link syntax is so ugly and I always forget what comes into which bracket in Markdown as this is simply not intuitive.
AsciiDoc can do so much more (table of contents, includes, level-offsets, powerful tables, etc.) - you can write professional books with it (e.g. O’Reilly uses it AFAIK for their books). I might also be biased but it would be even more awesome if users could change the default to their personal flavor.

Thank you for your answer. I’m taking note of AsciiDoc and I will explore it for that Wiki I was referring to.

However, my question was more about which exact flavor of wiki markups supported by GitLab is actually activated. I haven’t found an answer to that yet. Maybe I’ll have to delve into the source code :frowning: