In ModCP banned users page shows which user, for what reason, banned for how long, by whom.
It should also show which ban type user got, as there can be several ban types in MyBB.
by type you mean either username or IP banned, right?
No, I mean which usergroup that user moved to via banning, as there can be more than one.
User Groups > Edit Usergroup > "Yes, this is a banned group"
If this group is a 'banned' user group, users will be able to be 'banned' in to this user group.
For example in my forum I have 2 banned groups, first one is standard one which makes user unable to reach entire forum. The 2nd one makes user unable to reach "General Discussions" category, when that happens user is still getting alert, informing him that he is banned from all or some sections of this forum for what reason for how long.
When I look at banned users in modcp, I want to be able to understand which users got actual, entire forum ban and which users got different kind of section bans.