Re: That is just part of the story.....
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is redeemable at face value for current currency or coins. But not for silver or gold, even if they are silver certificates or gold certificates. The same is true of all coinage and postage stamps - it retains its face value and has never been devalued."
The USPS will not redeem unused postage stamps, but they can be used at face value if affixed to packages or envelopes for postage.