Board Thread:The Panopticon/@comment-2162194-20130713192557/@comment-5918438-20160127040035

I like that angle, actually. The source didn't invent "hir" as a pronoun, so standard rules apply. So ze/hir/hirself is totally acceptable even though we've only actually seen hir (both as object and as possessive) and hirself used.

And indeed, "hir" was used in print outside the DWU as early as 1988. Interestingly, though, that source which I found uses "hir" in the subject too.