Ok, you CAN use short urls as long as they dont mask the host's url. For example, you can use 2ya.com if you unmask it which means when you go to blahblah.2ya.com it'll redirect to blahblah.bizhat.com and everyone can see bizhat in the search bar. So it is allowed to a certain level. So dot.tk will not work for this.

cjb.net and 2ya.com would work.

Please dont post ambassador number cause when we enter that you get promotions/prizes. It is unfair for people to think this number is something special. It is nothing and everybody can register without a number.