The practical analogue of understanding an 'order' vis a vis the truth-conditional understanding of a statement

To know what a statement means is to know under what circumstances it would be true (Tenet of truth-conditional semantics). And a good tenet.

When it comes to non-alethic, it is not as if a new faculty of the understanding or mind or soul is appealed. No. It is still a matter of GRASPING.

To understand what an order MEANS is to grasp under what circumstances it would be fulfilled (satisfied).

Tarski tried to define 'true' in terms of satisfaction, and succeeded. He opened the path for non-alethic modal logics, like deontic logic, and indeed Grice's System G. Etc.