[zegerjan]

The additions GitLab has expand on Markdown. For example, if you comment with a string of hexidecimals larger than 8 characters, GitLab will try to link to the commit if it finds one. For issue 1, the reference pattern in #1. This is convenient in cases where you want to cross reference merge requests, snippets, and others, without copy pasting the links. The docs explain it better than I could: https://docs.gitlab.com/ce/user/markdown.html

But in general, GitLab supports Markdown, with a few extensions.