Currently there are two hooks for when a user is blocked in SpecialBlock, BlockIp and BlockIpComplete, but none for unblocking a user in SpecialUnblock. So if an extension needs to reliably add and remove information about user blocks that extension will never be able to hook in to see when a user block is removed through SpecialUnblock.
At a minimum a similar UnblockIpComplete hook would be ideal.
Version: 1.20.x
Severity: enhancement