It could be unit specific. I haven't seen this security measure order copied over to any other unit diary of that period.
From reading the diaries there is a shift of style with the OC changeover; I get the impression the 17 Const Sqn OC in that period is um, very thorough and busy. The RAE orders include a list of all Australian and NZ casualties, SOP orders for all sorts of things incl. shirt sleeves, smoking in vehicles, postal, VD, taxation, sport, vehicle inspections, and a reminder that you MUST get your molybond through 8 Pet Pl RAASC not 2AOD using form xyz etc.
Here's another, jul68, regards the Acco fleet.
