When I was not logged in, this talk page presented me with the following message:
- You do not have permission to edit this page, for the following reason:
- The action you have requested is limited to users in the group: Users.
"Users" was a red link to ArchivesWiki:Users. I wonder which people the permission is really limited to! Clearly I can edit this page now, despite not being named on that redlinked "group" "project page" (which I could also edit, apparently, but I'll leave that for the person who created the link to it and presumably has planned specific content for it).
Maybe, however, the message to not-logged-in visitors should refer to a special page (e.g. Special:ListUsers - Hmmmm - now I see why Sam's talk page was empty...) or a category rather than to a manually-created list?
A newish wiki, of course. Doubtless I will find other amusing quirks.