Ing. Jiří Sedlák
- Vice-President of the Organizing Committee of the World Stamp Exhibition PRAGA 2008.
- International FIP juryman for the Traditional Philately Class and juryman for the Philatelic Literature Class.
- Chairman of the Society of Collectors of Czech and Czechoslovak Stamps attached to SCF and a member of the Typological Commission.
- Collects Czechoslovak stamps and postal operation 1945 – 1955 and stamps of the Czech Republic, co-author of the book “Ocelotisk z plochých desek (Recess Printing from Flat Plates)”.