Board Thread:Support Requests - Getting Technical/@comment-28947388-20170130205153/@comment-1757994-20170130211749

MediaWiki:Editnotice-* allows messages at the top of the page when certain pages are edited, but not when they are read.

If you want a notice when they're read, I think JavaScript is the only option. Otherwise, you'd have to add a template manually and try to enforce that it always existed on every page.