![](http://www.brundledan.com/flux_anim.gif)
The rule is that you're supposed to "ping" any poster you might be referencing in a message to another poster. (This condition is especially popular among FR's Official Sewing Circle, which tends to demand "courtesies" it's rarely willing to extend to others.)
Sometimes, gosh darn it, I just forget to do that. ;)
-Dan