PermGen documentation?

I have experienced the PermGen out of memory error. I see that folks are saying to set -XX:MaxPermSize=256mThe problem is, no matter how much documentation I scour I can not find this in anything on suns website. Where can I find info on this setting?
[272 byte] By [_dnoyeBa] at [2007-11-26 18:05:28]
# 1
Go to http://java.sun.com/javase/technologies/hotspot/vmoptions.jspScroll down, because it is a long page ;)
joneloa at 2007-7-9 5:36:05 > top of Java-index,Desktop,Runtime Environment...