§ 1-204. Mandatory, prohibitory, and permissive terms.

(a) Mandatory terms.

"Must" and "shall" are each mandatory terms used to express a requirement or to impose a duty.

(b) Prohibitory terms.

"Must not", "may not", and "no ... may" are each mandatory negative terms used to establish a prohibition.

(c) Permissive terms.

"May" is permissive.