Easy navigation between pages on same topic for different versions of Drupal

We already have many pages that covers the same topic for D7 and D8 – and maybe there will be more versions supported in the future. Many of the topic pages even have the same URL pattern:

https://www.drupal.org/docs/8/system-requirements VS https://www.drupal.org/docs/7/system-requirements and many of their sub pages.

If you want to guide a user to the same documentation for a different version of Drupal, your best bet is “Related content” at the bottom. It doesn’t look good and it is a manual task adding and maintaining those links (example 1, example 2, …)

I guess this could wait for the “Documentation initiative” to start rolling, but I think it’s a pretty lowing hanging fruit that would benefit our users greatly – similar to #1413004: Add Drupal versions to page title for more clarity and better SEO.

Suggested (temporary) solution

If there exist version specific “duplicate” URL aliases (as the system-requirements example above), then we add a version switcher some where visible on the page – maybe in a fashion similar to symfony (example).

This requires that we are slightly better at setting good URL aliases and probably turning of automatic URL aliases completely – which is a good thing anyway.

Source: https://www.drupal.org/project/issues/rss/documentation