[§583-10] Additional parties. If the court learns from information furnished by the parties pursuant to section 583-9 or from other sources that a person not a party to the custody proceeding has physical custody of the child or claims to have custody or visitation rights with respect to the child, it shall order that person to be joined as a party and to be duly notified of the dependency of the proceeding and of that person's joinder as a party. If the person joined as a party is outside this State the person shall be served with process or otherwise notified in accordance with section 583-5. [L 1973, c 88, pt of §1; gen ch 1993]