Most subcastes have an elaborate system of exogamy. They are
either divided into a large number of sections, or into a few
_gotras_, usually twelve, each of which is further split up into
subsections. Marriage can then be regulated by forbidding a man to
take a wife from the whole of his own section or from the subsection
of his mother, grandmothers and even greatgrandmothers. By this means
the union of persons within five or more degrees of relationship
either through males or females is avoided, and most Banias prohibit
intermarriage, at any rate nominally, up to five degrees. Such
practices as exchanging girls between families or marrying two
sisters are, as a rule, prohibited. The _gotras_ or main sections
appear to be frequently named after Brahman Rishis or saints, while
the subsections have names of a territorial or titular character.