Mass. Gen. Laws ch. 203E, § 304: Representation by person having substantially identical interest

Section 304. Representation by person having substantially identical interest

Unless otherwise represented, a minor, incapacitated or unborn individual or a person whose identity or location is unknown and not reasonably ascertainable, may be represented by and bound by another having a substantially identical interest with respect to the particular question or dispute, but only to the extent there is no conflict of interest between the representative and the person represented.