Link to documentation from wiki editor gives 404

Open a wiki-page for edit (I used https://gitlab.com/elygre/gitlab-test/wikis/home, but that is probably private)
Under the editor there is a line "link to a (new) page, simply type Link Title. More examples are in the documentation", where documentation is a link to https://gitlab.com/help/user/project/markdown#wiki-specific-markdown
https://gitlab.com/help/user/project/markdown#wiki-specific-markdown does not exist