NOT.2:4.6 - Retain usable conventions and controlled abbreviations

Keep the rule at the scale required by its next use. A legend and a worked construction can suffice for a local diagram; repeated automated processing can justify a grammar, parser or structural editor. A user must be able to recover any omitted structure that changes the operation.

For an abbreviation, give the expansion or another way to establish its meaning. If several expansions are allowed, show why the difference does not affect the intended use. NOT.4 handles the corresponding preservation argument. Retain a visible distinction when no such argument is available and the choice matters.

The method finishes with rules that permit the required construction and make its use recoverable, or with a specific unresolved formation or interpretation question. Teaching those rules and comparing their reading cost use the relevant learning and explanation methods; a more explicit syntax alone does not establish that a reader has learned it.