What is deontic?

Some articles on deontic:

Alan Ross Anderson - Deontic Logic
... He developed systems of deontic relevance logic containing a special constant v (notation varies) for this purpose ... Such systems have sometimes been characterized as "reductions" of deontic logic to alethic modal logic ...
Modal Operator - Modality Interpreted - Deontic
... Deontic modal operators (P-operators) influence the construction of possible worlds as proscriptive or prescriptive norms, i.e ...
Subjunctive Possibility and Other Modalities - Deontic Possibility
... in language between subjunctive possibilities and deontic possibilities for example, we sometimes use the statement "You can/cannot do that" to express (i) what it is or is not ... possibility as there are some important differences in the logic of subjunctive modalities and deontic modalities ... But in this non-ideal world, a deontic ‘must’ does not carry the moral certitude that people morally must do such and such ...
Modal Verb - Function
... of propositions being true or not true (including likelihood and certainty) deontic modality, concerned with possibility and necessity in terms of freedom to act (incl ... ("It is necessarily the case that you are starving.") deontic You must leave now ... Epistemic modals can be analyzed as raising verbs, while deontic modals can be analyzed as control verbs ...
Deontic Logic
... Deontic logic is the field of logic that is concerned with obligation, permission, and related concepts ... Alternatively, a deontic logic is a formal system that attempts to capture the essential logical features of these concepts ... Typically, a deontic logic uses OA to mean it is obligatory that A, (or it ought to be (the case) that A), and PA to mean it is permitted (or permissible) that A ...