Hello Rex and welcome to the Shack!
We don't have an invite feature so to speak, but you can go to My Profile under the
UserCP Menu and under the Forum Info section you will see a Referral ID link to invite friends. It will look like the following link where "
x" equals your user ID number.
Code:
http://www.hometheatershack.com/forums/index.php?referrerid=x
If a user uses this link to visit the forum and they click the Register link, it will automatically insert your username into the referral field during registration and give you credit for a referral.