Blacklist info
Must use a dropdown when blacklisting a player maybe 10 reasons like Harrasment, language, cheating, arrogance, excessively slow play, just a jerk, idk... too skilled for me?, whatever typical reasons people blacklist anyone.
Then have a a way to view everyone blacklisted to see why, who, and how many felt compelled to blacklist them.... maybe this might change some players behaviors.
You could even have a toggle option to allow the blacklisted player to message the blacklister to discuss/petition being un-blacklisted.
Having played with several hundred unique players I have three blacklisted, two for cheating in a FFA (admittedly) and one for complete arrogance, harrasment and language.
Use the private notes feature.