Sec. 311.016. "MAY," "SHALL," "MUST," ETC. The following constructions apply unless the context in which the word or phrase appears necessarily requires a different construction or unless a different construction is expressly provided by statute: (1) "May" creates discretionary authority or grants permission or a power. (2) "Shall" imposes a duty. (3) "Must" creates or recognizes a condition precedent. (4) "Is entitled to" creates or recognizes a right. (5) "May not" imposes a prohibition and is synonymous with "shall not." (6) "Is not entitled to" negates a right. (7) "Is not required to" negates a duty or condition precedent. Added by Acts 1997, 75th Leg., ch. 220, Sec. 1, eff. May 23, 1997. SUBCHAPTER C. CONSTRUCTION OF STATUTES