Cachets

noun

1. A seal, as of a letter.
2. A special characteristic or quality; prestige.

   "I remember when this diner was a quiet hangout, but lately it seems to be losing its cachet."

3. A commemorative stamped design or inscription on an envelope, other than a cancellation or pre-printed postage.
4. A sealed envelope containing an item whose price is being negotiated.
5. A capsule containing a pharmaceutical preparation.