thon ["o" pronounced as in "pond"] (pronoun, coined in the 19th century as a contraction of "that one") the ungendered singular third person pronoun: thon, thons, thonself.
My hackles rise at the infelicity of such constructions as "he or she", "he/she", or "s/he" (what do you do with "him or her" under that convention?). They rise even faster when I encounter sentences such as "Everyone should do what they are best at."
Thus, all Institute procedures are written using the eminently useful non-gendered third person personal pronoun "thon." Introduced in the 19th century by a British clergyman (as a contraction of "that one") it became popular enough on both sides of the Atlantic that it was included in Webster's Second International Dictionary of the English Language. However, its use declined after WW I and it did not make the cut for the Third International. If your procedure writer likes it, thon can use it to thon's heart's content.
Jack E. Leonard, Ph.D., CHMM, Preident
[For an interesting account of uses of the word, see the 1992 essay by Fred H. Barge, D.C., Ph.C. of LaCrosse, Wisconsin.]