What are some of the rarest or most famous stamps in philatelic history, and what stories are associated with them?
How did the introduction of the postage stamp change the postal system and communication in the 19th century?
What are some of the most valuable rare stamps ever sold, and what makes them so collectible?
How do countries decide which subjects or themes to feature on their stamps, and how often do they issue new designs?
What are the different types of stamps (e.g., commemorative, definitive, airmail), and how are they typically used?
How can collectors authenticate and assess the condition and value of a stamp collection?
