We need not consider whether the Judge was correct in ruling that the meeting of the defendant board was an "emergency" meeting as defined by G. L. c. 39, § 23A (as appearing in St. 1976, c. 397, § 5), and as used in § 23B (as appearing in St. 1976, c. 397, § 6) because the Judge made an alternative ruling, as a matter of discretion, declining to invalidate the questioned action of the board. Section 23B, as so appearing, provides, among other things, that a court "may invalidate any action taken at any meeting at which any provision of this section has been violated . . . ." We decline to accept the plaintiffs' suggestion that we treat the auxiliary verb "may" as meaning "shall," as to do so would do violence to the purposes for which § 23B was enacted. See Abbene v. Election Commrs. of Revere, 348 Mass. 247, 250-251 (1964). The Judge had discretion to invalidate or not (Nantucket Land Council, Inc. v. Planning Bd. of Nantucket, 5 Mass. App. Ct. 206, 213 ; Kelley v. Planning Bd of Dennis, ante 24, 26-27 ), and nothing in the record indicates any abuse of that discretion.