Danathor Sothyr
If you want to go strict English writing etiquette, since English does not have an officially recognized gender neutral singular pronoun for an unknown person, the proper pronoun to use has traditionally been to use the masculine pronoun (he, him, his) in formal writing.
The current movement, however, appears to allow for using they as a singular pronoun (see:
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)
There is a more... confusing (for the general public) movement to adopt completely new fabricated pronouns:
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All three options "should" be acceptible. The first option (masculine pronoun) is the most likely to offend someone intentionally or unintentionally, or open you up to them picking a fight with you. The second option (using they as a singular) is the one that is least likely to offend someone, unless it's the type of person to go on a grammar rant... Like this one... only the exact opposite. And the third option doesn't really have any widespread traction, and is most likely to make people laugh at you, unless you travel in **VERY** specific circles... But, if you did that, you'd most likely not be having problems with pronouns.
(and yes, Danathor, I'm aware that you were probably just giving Sothyr crap, but I was bored.)