This isn't a recent change, but it's auxiliary information people may find helpful.
In two articles in comp.sys.mac.games.adventure in June 2000, Ann GM wrote (edited together by Pam):
Every time you gain a rank, a portion of the experience is put into a pool for your clan. This extra portion is in addition to the regular cost of training, but then you get it back from the clan. About half of that gets divided up every few minutes to clanmates online, and the other half is split among all members of your clan, online or not, and gives no messages. There's a small bonus added to both halves, enough to make it a net positive effect, but not enough that people not in a clan should worry.The half that goes to clanmates online only gets distributed when there's enough to make it worthwhile. The minimum required isn't very big, but it's not zero. That helps keep members of big clans from getting spammed. Big clans earn experience more quickly, in absolute numbers, so they hit that minimum number more often in a day. But they also have more people online, so when they get clan experience, it's a smaller amount.
Compiled and edited by Pamela Greene <pamg@alumni.rice.edu>. Additions, corrections, and suggestions for this file are welcomed!