there are several relevant threads, such as
http://www.mudcat.org/thread.cfm?threadid=48972#738157
http://www.mudcat.org/thread.cfm?threadid=3260#16066
http://www.mudcat.org/thread.cfm?threadid=16239#154814
(copy and paste, I'm not bothering with 'clickie' & titles today)
more to be found if you search for "wrenning"