These are Postal Cards and postal articles, with an imprinted seal, which are only offered to you in the Belgian post offices.
Hereupon the "postograms" makes an exception. They donít have an imprinted seal.
The Postal Cards are being collected "new" and/or "used".
Usually when they are still "new" they are more valuable than when they are already "used". Yet, it often happens that the devaluation stamp has more value because of its rarity, and not because of the postcard where it is stamped on.
The undermentioned example shows us a domestic postal card with a paid answer, catalogue number 24. Normally this one is quoted 10 BEF, but through the abroad stamping "London" it is quoted 500 BEF. So, make sure you examine everything very carefully.