I am not a brahmana by birth but i am always amazed why everyone is always trying to define "Who is a Brahmana"?
Why isnt anyone trying to define Who is a Kshatriya, Who is a Vaisya etc?
No body here asked you whether you are a brahmin or not. Even if you are not a brahmin by birth, there is no harm, you can continue to participate in the discussions here.
Since this site has the tag name `brahmin', naturally most of the brahmin community members are getting attracted to this website. Each and every such member is trying to find out whether he is a `true brahmin' or not. If he is not, then the next question arises `what to make him a true brahmin'. Personally I feel there is nothing harm in discussing it in this forum and in this thread.
Probably a forum like `Kshatriya.com' or `vysya.com' will discuss whether a person is true kshatriya and vysya.
All the best