(a) Preferred evidence. If the claimant is the natural parent of the employee, preferred evidence of the ralationship is a copy of the employee's public or religious birth record. If the claimant is the natural child of the employee, preferred evidence of the relationship is a copy of the child's public or religious birth record.

(b) Other evidence of parent or child relationship.

(1) When preferred evidence of a parent or child relationship cannot be obtained, the Board may ask the applicant for evidence of the employee's marriage or of the marriage of the employee's parents if that is needed to remove any reasonable doubt of the relationship.

(2) To show that a person is the child of the employee, the person may be asked for evidence that he or she would be able to inherit the employee's personal property under the law of the state where the employee died or had a permanent home.

(3) In some instances the Board may ask for a signed statement from the employee that a person is his or her natural child, or for a copy of a court order showing that the person has been declared to be the child of the employee, or for a copy of a court order requiring the employee to contribute to the person's support because the person is his or her child, or for any other supporting evidence which may be required in order to establish that the person is the child of the employee.