Urkunden Prüfgebiet: USA (Unions-Ausgaben ab 1847)

Prüfer	Art des Attestes	Katalog	KatalogNr.
The Philatelic Foundation, (Prüferkommission)	Attest	Scott	2
PSE, Professional Stamp Experts (Prüferkommission)	Sonstiges	Scott	2
The Philatelic Foundation, (Prüferkommission)	Sonstiges	Scott	2
The One Cent Franklin Plating Archive, Richard Doporto (Sonstiges)	Attest	Scott	21
Crowe, William T. (Sonstiges)	Attest	Scott	21
Crowe, William T. (Sonstiges)	Attest	Scott	211
The Philatelic Foundation, (Prüferkommission)	Attest	Scott	226 - 240
Pinchot, S. & Daniel N. (Sonstiges)	Attest	Scott	229