Warhammer 40k - Lexicanum:Permanent link
The Permanent link (also called Permalink) tool creates a link to a specific version of a Lexicanum page, i.e. a permanent link to how a page looked like at a specific point in time. Normal links always lead to the current version of a page, but the Permanent link leads to the text as it was at the time when the link was created. This means that the text does not include any edits made since.
Be aware that "permanent" only refers to the main text as it was at that point in time. Files and templates used on the page are still shown at their most current versions, as well as any content transcluded from other pages.
The Permanent link tool can be accessed from the Tools tab at the left side of the screen.
The tool can also be accessed via the Special pages tools overview, subsection Redirecting special pages.
You can also simply click here.
In both latter cases you will need to enter the specific version's Revision ID.
After entering the Revision ID in the search field the wanted Revision of the page will be displayed and you can copy the Permanent link URL from your browser.
Accessing a prior version of a page from its Page history tab will display a link to that specific version in the URL and its corresponding Revision ID.
More on the Permanent link Wikimedia tool can be found here.