MediaWiki:Apihelp-query+lists-paramvalue-prop-public/en

Several visibility-related properties:

perm

public or private (set by owner), private is only visible to owner.

perm_override

hidden or approved (or not present), can be set by a moderator.

flagged

The list got enough flags to qualify for moderator attention.

hidden

The list is hidden and only visible to the owner and moderators (due to flags or explicit moderator choice).