Board Thread:Support Requests - Getting Started/@comment-38557027-20190703213903/@comment-9605025-20190707021109

Just to reiterate, the whole $1 thing is specific to the welcome tool and only applies to the relevant MediaWiki messages. Even then, the meaning of $1 depends on the message you are editing. For regular pages, you can link to the viewer's own user page using the special page Fandyllic mentioned. If you simply want to display the viewer's username and not necessarily link to the user page, you can use InputUsername.