At the moment, a user will be reported as blocked even if the block is hidden (and even if the check user does not have rights to see hidden blocks).
If the Preliminary Check is only meant to be public data (as suggested in T237039), should this be changed?
Originally from T237296#5697205.
I did not know hidden blocks were a thing.
@dom_walden Are hidden blocks only visible to admins? Or a selective group of users?
I am not sure where the best documentation for this is. It is mentioned briefly here: https://www.mediawiki.org/wiki/Help:Blocking_users
@dom_walden Are hidden blocks only visible to admins? Or a selective group of users?
On enwiki, in theory only Oversighters can see them (requires the hideuser permission).
However, Check users seem to have some visibility. They can see a hidden user's block log, and can see that a hidden user is blocked in Special:Contributions (but cannot see the edits). Normal users cannot. I am not sure if this is deliberate.
That said, the current behaviour of Special:CheckUser is that it shows hidden users, hidden blocks and hidden edits.