This plugin allows MyBB to display ban reasons and expiration dates publicly on the forums. By default, ban information is displayed on the user's profile and as their signature. You can configure this as you prefer in the plugin settings.

Support for usergroup based permissions has also been added, allowing you to select which banned usergroups will be affected by this plugin. (For example, if you want ban reasons to display publicly for generic bans, but want them to stay hidden for users banned for sensitive reasons, you can set up two banned usergroups and enable only the primary banned usergroup for this plugin. )

This plugin is designed for MyBB 1.8, but should be backwards compatible with MyBB 1.6.x forums as well. Licensed under the GNU GPL, version 3. (Github link)

#disclaimer: not responsible for any forum drama caused by this plugin.