For what it's worth, the Queensland Museum History Section had some major
problems with losing accession numbers on objects. Our standard approach
now is to put the accession number on with Paraloid and to physically
wire or otherwise firmly associate a more detailed label, sealed in
plastic, to every accessioned item. (Suspenders *and* Belt). While we
occasionally find an item that has lost one or the other, we heven't yet
lost both - as far as we know.
 
Peter Volk
Social History
Queensland Museum