Unissued stamp - A stamp officially prepared for postal use but never issued due to, for example, an error in design or inscription, sudden changes in political regime or postal rates.
Universal Postal Union - (Formerly General Postal Union) - The General Postal Union was created by the Bern treaty on October 9, 1874 in order to form a single postal territory for the reciprocal exchange of correspondence between member post-offices. Within a year, they had adopted most of the principals previously set down by the International Postage Association and the Paris Postal Conference of 1863 in regard to uniform mail rates and regulations. Prior to this agreement, each country had to make an individual treaty with every other nation to regulate international mail. The initial signatories of this treaty were Germany, Austria-Hungary, Belgium, Denmark, Egypt, Spain, France, Great Britain, Greece, Italy, Luxembourg, Norway, The Netherlands, Portugal, Romania, Russia, Serbia, Sweden, Switzerland, Turkey, and the United States. In 1878, they changed their name to the Universal Postal Union, and they became a special agency within the United Nations in 1948. All but a handful of nations belong to it today.
The Ottoman Empire joined the UPU on September 15, 1876.
UPU - Abbreviation for the Universal Postal Union.(Formerly General Postal Union) - The General Postal Union was created by the Bern treaty on October 9, 1874 in order to form a single postal territory for the reciprocal exchange of correspondence between member post-offices. Within a year, they had adopted most of the principals previously set down by the International Postage Association and the Paris Postal Conference of 1863 in regard to uniform mail rates and regulations. Prior to this agreement, each country had to make an individual treaty with every other nation to regulate international mail. The initial signatories of this treaty were Germany, Austria-Hungary, Belgium, Denmark, Egypt, Spain, France, Great Britain, Greece, Italy, Luxembourg, Norway, The Netherlands, Portugal, Romania, Russia, Serbia, Sweden, Switzerland, Turkey, and the United States. In 1878, they changed their name to the Universal Postal Union, and they became a special agency within the United Nations in 1948. All but a handful of nations belong to it today.
The Ottoman Empire joined the UPU on September 15, 1876.
Used abroad - Where stamps from one country are used and cancelled in another. Quite common in cases such as British Colonies or Possessions. Spain and France also were countries that issued stamps that were used in other areas of the world over which they had influence. These stamps can only be distinguished by the postmark applied.
Used fiscally - Postage stamps inscribed with postage and revenue and used for the payment of revenue charges.