World Stamp Catalogue/Common themes

It is common for two or more countries to commemorate an event or famous person at the same time by the issue of a stamp.

To accommodate this we will try to co-ordinate the numbering of the stamps when this has occurred. In order to accomplish this we are reserving certain numbers for this purpose. These will be in the range between xxx-yyyy-11nn and xxx-yyyy-19nn, where "xxx" represents the country code, "yyyy" represents the year, and "nn" represents the numbers for the stamps in that set. For a variety of reasons it may not be possible to co-ordinate the numbering of the stamps within a given set, but it will be attempted where it practical to do so.

Common themes