Definitions for "Postal Card"
a mailing card produced by the post office, as opposed to a privately produced post card. A postal card has a stamp-like indicium. Since 1999 Postal Cards have been sold for 1ยข over face value. Scott numbers begin with UX. see also Denominated Postal Cards.
a card for sending messages by post without an envelope
a typically rectangular piece of thick paper or thin cardboard intended to write on and be mailed without an envelope and at a lower rate than a letter