To avoid falsification:
(i) Don't delete or insert negatives (as in example 19).
(ii) Do delete or update time adverbials, or convert to non-deictics (20).
Today in the lead sentence of a wire story must usually be updated (to
yesterday), converted to a non-deictic (on April 25), or deleted
altogether.
(iii) Don't approximate time and place adverbials with non-congruent
expressions (21).
(iv) Don't substitute non-congruent lexical items (18).
(v) Don't delete or insert expressed agents.
(vi) Don't reverse the transitivity of verbs.
Copy editors often change an active intransitive verb into its passive
transitive equivalent, or vice versa. This implies either the insertion or
deletion of an agent, which may not always be warranted by the input
copy. P A's version in ( 42) deleted the expressed agent: the legislative
acts which increased police powers in South Africa. The transitivity of
increasing is now ambiguous. XA's subsequent change to active intransitive
implies that police powers increased by natural growth.