VA will accept signatures by mark or thumbprint if:

(a) They are witnessed by two people who sign their names and give their addresses, or

(b) They are witnessed by an accredited agent, attorney, or service organization representative, or

(c) They are certified by a notary public or any other person having the authority to administer oaths for general purposes, or

(d) They are certified by a VA employee who has been delegated authority by the Secretary under 38 CFR 2.3.