In copy editing, the syntactic choices made in the input text are renegotiated.
Syntactic editing rules are either applications, reversals, or
alternatives. If the original version chose not to apply any particular rule of
grammar, the editor may reverse this choice and apply the rule. All the
optional rules of a normal grammar are potential editing application rules.
Particularly common are auxiliary and negative contractions, there insertion,
passivization, agent deletion, and relative clause reduction. Such rules
belong in any grammar of English, and all the copy editor does is take
options which were not applied previously.