Public forums are all well and good...but from time to time you have an occasion where something needs to be passed on to just one [or a few] individuals without inviting scrutiny and/or flame from coincidental audience.
Clicking on a User's Name in a post/thread will pop up a menu of options, one of which is "Private Message".
It's an invaluable tool for Admins and Mods...but it's also handy for all.
Don't foget to use it [and perhaps check [Just below the Welcome bar] for messages for you that may be languishing unnoticed....