Changed guide title to “Red Hat Technical Writing Style Guide”. Changed subtitle to “Style Conventions for Writers and Editors”.
Added inclusive language guidance.
Added section on use of relative pronoun “that”.
Added sections on exclamation points and referring to punctuation marks.
Clarified that sentence case is required for captions, legends, and diagram labels.
Added section on phrasal verbs (two-word verb forms).
Added more categories of ambiguities to avoid.
Dates and Times: Changed times of day standard from “a.m.”, “p.m.” to “AM”, “PM”.
Usage A-Z added entries: appendixes, as long as, blacklist, colocate/colocation, display, following, i.e., indexes, login/log in/log in to, master, sign in/sign in to, slave, whitelist, wish
Updated entries: backwards-compatible, high-availability, hostname, lifecycle, OK, please, setup, username, ZIP Code
Removed guidance about DocBook and markup, to focus instead on writing.
Minor edits so the guide itself conforms more fully with its own advice.