… Postage or revenue stamps, stamp-postmarks, first-day covers, postal stationery (stamped paper), and the …
Explanatory notes
… 97.04 ‑ Postage or revenue stamps, stamp‑postmarks, first‑day covers, postal stationery (stamped paper), and the … all kinds , i.e., the stamps of the kind normally used for affixing to correspondence or postal packages; “postage due” … Postage stamps stuck on envelopes or cards , including “ first‑day covers ”, which are envelopes, usually marked …