Section 50
Opinion on relationship when relevant
When the court has to form an opinion as to the relationship of one person to another, the opinion expressed by conduct as to the existence of such relationship of any person who as a member of the family or otherwise has special means of knowledge on the subject, is a relevant fact.
(2)
Such opinion shall not be sufficient to prove a marriage in prosecutions under section 494, 495 or 498 of the Penal Code
[Act 574].
(a)
The question is whether A and B were married.
The fact that they were usually received and treated by their friends as husband and wife is relevant.
(b)
The question is whether A was a legitimate son of B.
The fact that A was always treated as such by members of the family is relevant.
Act 56