I thought they were he, she, it...
.
Ah, those were the days when "Elements of Style" by Strunk and White, was a well regarded guide in writing and journalism. Pronouns were informative and placid, part of a millennium of evolution in the World's most polyglot yet versatile language, English.
Now, like much else, the control of language usage has been preempted by the LEFT and their MSM Minions, so we are subjected to promiscuous pronoun proclivity to the point where I am quite glad I can never be summoned before a Human Resources Tribunal for misuse, deliberate or otherwise! I do not wish to be forced to use a grammar overlord that reminds you, like the late UNLAMENTED Microsoft 'Clippy', to stop and consider the proper pronoun for your addressee, he/she/xer and whatever gets added by their progressive prions!