Stop branch creation

[Rajesh Patwardhan]

Hello All,
I was wondering if any one has implemented a script to stop branch creation
by users other then a chosen few. I did search on Google, but did not get
any results. 
Any help or pointers on how to get some information from the Taginfo hook
will be greatly appreciated. When I did a trace I got a reason=add on both
cases of creation of a tag as well as branch Tag. 
Regards,
Rajesh