Thank you, mwaterous! This works perfectly.
Now, the profile link is “follow”, the url link in messages continues to be “nofollow” and the HTML link (<a) continues to be “follow”. So this will be the only issue… it is just too tempting.
As for spam, yes, I am walking on the razors edge. But the forum is by invitation/contribution only. Not for anyone that wants to register. As members contribute, I figure a real link is the least I can offer… as in gratitude.
How do I file a trac for #1 problem?