Rejoining players - Kick message shown
I propose that when players who have left/been kicked from the clan rejoin, there is a description of why they left/who kicked them.
For example. I kick said player and put the kick comment as "Abusive language, low donations." Then if they ever try to reapply it says, kicked by MattyG17 - Abusive language, low donations.
I don't know about others, but sometimes it can be hard to remember exactly why a person was removed from the clan in the first place. Or if I am not online then my Elders will know why they were removed. Hence not having to deal with the rotten players twice.
Perhaps also players that leave the clan are able to write a leave message which goes to the clan leader. This can also be shown upon reapplying.
P.S. I realise this is similar to the blacklist, but offers the opportunity for second chances.