Konstantin Penkov

All Cinderellas (promotional labels) Countries of the world collected globally Fields related to postal history and postal operations Forgeries (exhibits devoted to identifying forgeries) Other unspecified fields of philately Perfins Special stamp products and their variants Specialisation in the design and production of stamps, postal stationery and other securities; types, plate flaws, … Stamps and postal stationery for special postal use Thematic fields

All Period before the founding of the UPU in 1874 Period from the end of World War II to the present Period from the founding of the UPU (1874) to the end of World War II

All Aerophilately class Astrophilately class Court of Honour – official exhibits of postal museums and postal administrations Exhibits promoting philately Literature class (online literature) Maximaphily class Open class Other unclassifiable exhibits Picture postcard class Postal history class Postal stationery class Revenue and fiscal philately class Stolen philatelic collections and material Thematic philately class Traditional philately class