Reuse and localize descriptions
Static messages can be reused with the grammar's #= path form when the declaration contract permits it. Localized description variants belong to the declaration's source language identity; they are not runtime interpolation. Reusable messages and translations have their own source forms in the syntax reference.
Good descriptions state business meaning, especially for public operations, exposed reports, fields, and UI labels. Generated application reference material is derived from checked declarations and their descriptions. It cannot document unstated policy accurately; keep the source description close to the owning contract. For exact attachment rules, see source syntax.