A. "Shall" and "must" express a duty, obligation, requirement or condition precedent.

B. "May" confers a power, authority, privilege or right.

C. "May not", "must not" and "shall not" prohibit the exercise of a power, authority, privilege or right.

History: Laws 1997, ch. 173, § 4.

Effective dates. — Laws 1997, ch. 173 § 22 made the Uniform Statute and Rule Construction Act effective July 1, 1997.

"Shall" and "must". — The words "shall" and "must" generally indicate that the provisions of a statute are mandatory and not discretionary. State v. Lara, 2000-NMCA-037, 129 N.M. 391, 9 P.3d 74.

Mandatory or directory. — The question of whether a statutory requirement is mandatory or merely directory is answered by looking to the intent of the statute. Stokes v. Tatman, 1990-NMSC-113, 111 N.M. 188, 803 P.2d 673.

"May" contrasted with "can". — In the context of the annexation statutes and the statutes relating to municipal planning, the word "may" in Section 3-7-15A NMSA 1978, cannot reasonably be interpreted as "can." City of Albuquerque v. State Mun. Boundary Comm'n, 2002-NMCA-024, 131 N.M. 665, 41 P.3d 933.

"Shall" and "may" not interchangeable, legislative intent determines use. — Whether words of statutes are mandatory or discretionary is a matter of legislative intent to be determined by consideration of the purpose sought to be accomplished and the general rule is that the words "shall" and "may" shall not be used interchangeably. State ex rel. Robinson v. King, 1974-NMSC-028, 86 N.M. 231, 522 P.2d 83.

Directions not essence of duties not mandatory. — Directions in a statute which are not the essence of things to be done are not commonly considered mandatory, particularly where failure to comply does not result in prejudice. State v. Lindwood, 1968-NMCA-063, 79 N.M. 439, 444 P.2d 766.

If public interest involved, public officer's power is mandatory. — Where a public officer is clothed with power in permissive form to perform an act in which the interests of the public are concerned, the permissive language of a statute will be construed as mandatory. State ex rel. Robinson v. King, 1974-NMSC-028, 86 N.M. 231, 522 P.2d 83.

When "shall" mandatory. — A claim for relief "shall contain a short and plain statement of the claim showing that the pleader is entitled to relief," and that "each averment of a pleading shall be simple, concise and direct." The word "shall" is mandatory. Mantz v. Follingstad, 1972-NMCA-164, 84 N.M. 473, 505 P.2d 68.

"Shall" held mandatory. — "Shall" in Section 31-1-3 NMSA 1978, and in former Rule 40, N.M.R. Crim. P. (now Rule 5-607), is mandatory. State v. Davis, 1982-NMCA-057, 97 N.M. 745, 643 P.2d 614.

When permissive language mandatory. — Permissive language may be construed as mandatory when it plainly appears that the legislature intended to impose a ministerial duty upon a public official or agency rather than entrust the agency with a judgmental function. A mandatory construction is normally suggested when the public or an individual has a claim de jure which demands that the power conferred upon the administrative agency be exercised for the benefit of that claim. 1971 Op. Att'y Gen. No. 71-104.