4 a. Be careful in the use of ambiguous words, e.g. "certain."
5. Be careful in the use of "he," "it," "they," "these," &c.
6. Report a speech in the First Person, where necessary to avoid ambiguity.
6 a. Use the Third Person where the exact words of the speaker are not intended to be given.
6 b. Omission of "that" in a speech in the Third Person.
7. When you use a Participle implying "when," "while," "though," or "that," show clearly by the context what is implied.
8. When using the Relative Pronoun, use "who" or "which," if the meaning is "and he" or "and it," "for he" or "for it." In other cases use "that," if euphony allows. Exceptions.
9. Do not use "and which" for "which."
10. Equivalents for the Relative: (a) Participle or Adjective; (b) Infinitive; (c) "Whereby," "whereto," &c.; (d) "If a man;" (e) "And he," "and this," &c.; (f) "what;" (g) omission of Relative.
10 a'. Repeat the Antecedent before the Relative, where the non-repetition causes any ambiguity. See 38.