Simple! AddOn works as normal, except when you (somehow) move a character to be a sub-character of another ie. like a tree with branches. It would then have a little [+] box next to it, click that and it shows all the alts for that player (they are still on your friends list, just organised!)
It would only need to do one level of organising, no need for Friend->Sub->Sub etc. just Friend->Sub(*8) :)
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Organise Friends List
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