She watched him press his rubber stamp across the green card in sharp blue ink.

“If someone signs for this at their reception desk, when does the return receipt come back to my mailbox?” she asked.

The clerk handed her the thin paper receipt stub.

“Three to five business days, depending on how fast their mailroom handles incoming deliveries.”

Caroline slid the narrow green slip into her leather wallet, right behind her driver’s license.

“Keep that tracking number safe,” the clerk said, sliding her change across the counter.

“Once it’s delivered, the signed green card is your legal proof of receipt.”