The information below is no longer valid, please check Mehni's reply before.
Posting this brief guideline here, since it was a suggestion over a Steam message to myself.
In the definition files, the game uses keywords like HECAP and HIS to insert a pawn's pronouns into a backstory description. Some official language translations, like French, use conditional statements like {PAWN_gender ? he : she} to select pronouns for text.
A typical backstory might read like this:
HECAP found himself stranded on a rimworld with nothing except for HIS dog.
Anyway, for wiki readability it's nice to translate these programmer keywords to regular words.
Instead of deciding all the the backstories should be male pronouns, female pronouns, 50-50, or at random; gender neutral pronouns should be used.
HECAP -> They
HE -> they
HISCAP -> Their
HIS -> their
Some additional discretion needs to be used for some statements like 'he is', because 'they is' isn't grammatically correct.
HE was -> they were
HE is -> they are