Re: Wailay Log (Free Minutes)
They do marry within caste, but not in same lineage, for instance, I am of Gandhar gotra, so all jatts and Jats having same gotra are my brothers and sister 
No surname gives away the lineage, a Siddhu and Sandhu are of two different lineage, problem is in brahmins as surname defines religious qualification or place of birth, not gotra