It is appointed to the couple by the state not the federal government.Also there are different laws in each state toward getting a marriage license.
The word "Dalit" means "oppressed" in Sanskrit (in which the word actually has a form "dalita").
It comes from the root "dal" which means broken or oppressed.
Dalit is the name that the Dalits are using themselves, and another word for the group is "Untoucheable"