Yay, my badgers have come to the dam!!!
Quote: "Using masculine pronouns is acceptable when the subject of a sentence's sex is unknown. They/their is becoming more commonly used but is generally incorrect."
True, I've admittedly used "them/their" before because I wasn't sure. Interestingly, it is debatable whether they/them/their can be used in singular, though I tend towards agreeing with the plural use for conformity to all standards (Chicago Manual of Style takes no stance on this, last I checked -- fence-sitters!) There are a new-ish set of gender-neutral and -agnostic pronouns and honourifics but I don't think they've been formerly adopted and there's lot's of fragmentation so I don't foresee an ISO (or similar) standard any time soon:
Mx = Mr/Mrs/Ms
Others floating about:
Zhe/Zir/Zhir/Ser
Reality:
Ther word "man" used to refer to human, not a gender division thereof. The common usage changed, leading to the PC (Politically Correct) nonsense of today -- with regard to genders at least.
From the standpoint of a writer, I find all this a little silly to be perfectly honest. At the same time, I do sympathise with people who don't want to be defined within a gender binary. I would therefore propose the standard of replacing all gender-identifying components of any pronouns and honourifics with "xhe" and "Xh[a]" respectively. Rationale: less complicated than other crap:
he/she = xhe
his/her = xheir
him/her = xhem
Mr/Mrs/Ms = Xh
Master/Madam = Xham
Lord/Lady = Xhal
King/Queen = Xhan
Prince/Princess = Xhap
Duke/Duchess = Xhad
Cool, ready to write that science-fiction novel now.
Conversely we could just pull Japanese into our lexicon since Japanese has a ton of agnostic terms. And before anyone asks, yes, it will blend
"I was in nASA before it was cool" -- Original nASA Members (nonZero, DJD and TheComet)