Hello Ted, I have to admit not to have been following too closely recent exchanges over A.I.R. but I have a relative, Lt. R.E. Walsh, late of the 44th Bn, AIF who had a long "apprenticeship" in military matters. He became involved when barely a teenager and at the point where he volunteered for overseas service, in his case, February 1916, he had previously been in the "A.I.R." I say this, not exactly with my hand on my heart, because I have not been handling R.E.W.'s papers for a time now, but I feel sure that this is the case. When I enquired about this abbreviation it appears to have been a nomenclature used during an early period before there was actually an A.I.F., i.e. after Federation but before the "serious" build up to WW I. A kind of "limbo" period. I'll follow closely now. Regards, Julie