This is the official dba.se guidance for canonical links - although it is not guaranteed to be up-to-date (and currently it is slightly out-of-date).
See the comments below this post for a list of magic tags and their renderings. Hover your mouse over the rendered magic link to see a tooltip of the target URL. The follow examples are excluded because they are context-specific.
You can find a magic link reference in Markdown Help section of SO proper, particularly the Comment formatting section. The dba.se guidance does not have the July 10 update at this time.
Additionally, Some magic links are only enabled on request. Before we had an MCVE page, there was nothing for
[mcve] and its synonyms to link to. A community manager had to create the page then ask a developer to change the code so that
[mcve] and the others worked on this network. The page that
[mcve] links to is editable by moderators. The (current) synonyms are
/help/reprex urls go to the same page.
* from chat