Should isn’t certain and allows clarification of the plan as the CP – it’s not affirmative language that requires binding decisions
Mulligan 18 ---- Stephen P., legislative attorney for the Congressional Research Service, J.D. (Loyola University Chicago School of Law), “Withdrawal from International Agreements: Legal Framework, the Paris Agreement, and the Iran Nuclear Agreement,” 5/4, R44761, https://fas.org/sgp/crs/row/R44761.pdf
Whether a U.N. Security Council resolution imposes legal obligations on U.N. Member States depends on the nature of the provisions in the resolution.188 As a matter of international law, many observers189 agree that “decisions” of the Security Council are generally binding pursuant to Article 25 of the U.N. Charter,190 but the Security Council’s “recommendations,” in most cases, lack binding force.191 Whether a provision is understood as a nonbinding “recommendation” or a binding “decision” frequently depends on the precise language in the resolution.192 Commentators have noted that the Security Council’s use of certain affirmative language, such as “shall” as opposed to “should,” or “demand” as opposed to “recommend,” may indicate that a resolution is intended to establish legally binding duties upon U.N. Member States.193