stamps on stamps
stamps on stamps is a postage stamp or commemorative stamp.
Overview
Catalogue entries for stamps state issue, perforation, gum and certification. VALÉORINE records this subject so that lots referring to it can be described consistently.
In detail
stamps on stamps is a postage stamp or commemorative stamp.
Sources
Each source is named with the standing the house places on it, so the evidence can be weighed rather than taken on trust.
reference work · Reputable secondary · Wikipedia
“Stamps on stamps”, English Wikipedia, consulted as further reading
Consult the sourcereference work · Reputable secondary · Wikidata
Wikidata, structured authority record Q854440: stamps on stamps
Consult the source