C2Cigars is correct. If the postage stamps were included in packs of cards, they would be allowed. Postage stamps issued by themselves by cetain postal systems do not meet the guidelines for inclusion here. Please remember, this is a Trading Card database, not a sports collectibles database. We also handle a ton of non-sports and gaming cards. If we added these, we would then need to list flower series, car series, etc.
-- Dan --
Note: Please see my profile for more info regarding trading (section updated 3/4/2024). I have added a large portion of my inventory to the site, and currently have trading turned on (details are in my profile).