Stamping for Postal Delivery
Puzzle 1 of Best Friends Easy Pack
Question is: Stamping for Postal Delivery
and the answer is: FRANKING
Word Meaning:
FRANKING — (countable) A device or marking such as postage stamp, printed or stamped impressions, codings, labels, manuscript writings, or any other authorized form of markings affixed or applied to mails to qualify them to be postally serviced.
Definitions from Wiktionary.