Section 49 of Evidence Act 1872

Opinions as to usages, tenets, etc., when relevant.--- When the Court has to form an as to –

The usages and tenets of any body of men or family,

The constitution and government of any religious or charitable foundation, or the meaning of the words or terms used in particular districts or by particular classes of people,

The opinions of persons having special means of knowledge thereon, are relevant facts.