On the wiki the special pages linked in the toolbar can provide important information or act as tools to find things on the wiki.
Permanent links
[[Special:Permalink/<oldid>]] links to a specific revision of a page. A revision's ID is the "oldid" in the URL of any revision. To get a revision of a page, view the page's history and use the revision timestamps to find the "oldid". This works even with the latest revision of a page. Example
[[Special:Diff/<oldid>/<diff>]] links to a page diff, equivalent to the "diff" link on edits or the button in page histories. The oldid is the older revision of the page while the id used for the diff is the newer revision. Example