If you would like to invite people from other forums to participate in the 1.3CP board, you need to vouch for them in the VOUCHING TOPIC.
NOTE: Be absolutely sure that the vouchee is registering on BZU with the same name as you mention for vouching. Otherwise said vouchee may be mistakenly rejected.
NOTE 2: After being accepted, the vouchee has to click on the account activation link sent to his/her email inbox.
Vouching topic link (http://www.bzuniverse.com/forum/index.php/topic,7683.0.html)
For a list of Battlezone 2 affiliated websites, where potentially hundreds of community members just waiting to be invited into another community project reside:
List of Battlezone 2 affiliated websites topic link. (http://www.bzuniverse.com/forum/index.php/topic,8512.0.html)