This Catalogue contains the main postmarks of permanent post offices. Main postmarks are defined here, where the definition of all other kind of postmarks also appear. Markings from travelling post offices and non-postal services such as railway or shipping companies are not included. All postmarks have been catalogued, ranging from the first recognised postmarks from the pre-adhesive period to the year 1900. The only exception is the so called bridge-type postmarks first introduced in 1890. The valuation of the postmarks extends up until the collapse of the Austro-Hungarian Monarchy (1918), and those postmarks used after this period are marked with this symbol "+". This catalogue contains almost 11 300 postmarks in total and the tables in the entire Catalogue have more than 192 000 fields. A volume of such length, even with the greatest care and repeated proof-reading, can not be completely flawless. Any comments or additional information is gratefully accepted at the following email address: gudlin(at)gmx(dot)de