General.
(a) General. Where a nonresident person would otherwise qualify to participate in a group return permitted under sections 151.17, 151.18, 151.19 or 151.20 of this Part, except that such nonresident (or the spouse of such nonresident) has New York source income from sources other than the group, such nonresident shall, nevertheless, be permitted to elect to participate in the group return under the following conditions: