Note on catalog numbers used in collections: No commercial copyrighted catalog numbers or values are provided in the collection files.  Collections with the "Stampcat" catalog numbering system use the following stamp class characters (e.g., q112b is "airmail" class, number "112" of subvariety "b"): List of Stamp Classifications None for any type of regular issue "a" for Certified "c" for Postal card "d" for Air Postal card "e" for Envelope or Cover "h" for Regional Issues "j" for War tax "k" for Registered "l" for Newspaper "m" for Special Handling "n" for Revenue "o" for Local "p" for Semi-postal "q" for Airmail or Air post "qs" for Airmail Special delivery "r" for Airletter "s" for Special delivery "t" for Tax "u" for Military "v" for Postage due "w" for Occupation "x" for Official "y" for Postal Savings "z" for Parcel post "zv" for Parcel post postage due