The preceding chapter showed how sentences can be streamlined by reducing their adjective clauses to adjective phrases — a simple process that omits the relative pronouns “that,” “which,” “who,” “whom ...

An essential relative clause provides necessary, defining information about the noun. On the other hand, non‐ essential relative clauses provide additional, non‐necessary information about the noun.

Baltimore Sun copy editor extraordinaire John McIntyre uses the term “dog-whistle editing” to refer to tiny editing issues that only copy editors notice (and perhaps only copy editors care about).