Looking to add some documentation, I was reminded of the old and completely useless pages that should be filtered out of sight in some way so, in line with the proposal here — Proposal for Handling Old Pages — I added Retired and Archived categories at doc.tiki.org. Retired is admin-accessible-only and is for pages that no longer have useful information, and Archived is Registered-accessible-only and is for pages that may still have some value but that it's better for casual visitors and search engines not to see.
Probably most pages that will be affected by this sorting will go into Retired, but I thought the Archived category might be useful for borderline cases.
Of course many of the remaining pages have sections that are out of date, etc., but need to stay public. On these pages, I suggest that information referring to old Tiki versions that are no longer supported should be deleted from the page, if the information is counter to current practices or otherwise not helpful. It still exists in the page versions history if anyone needs to see it. A note could be added on the page explaining that, but this might just be more clutter so maybe it's better not to bother.