you would call someone person to person and they would say they're not here and you'd say I'll call back at 1:00 and that meant that you were arriving at the airport at 1 so you didn't have to pay for the call?
That reminds me when my brother was in college out of state. Collect calls cost more, so he'd place a collect call then we'd say the person wasn't available. But then we knew he was home and wanted us to call him back direct.
My cousin used to do that with his son when the boy was in college. He would use a code name (it was stupid like John Smith or something), my cousin would say that Mr. Smith was not home, and that meant that my cousin should call his son back at the dorm.
After graduation, my cousin's son was offered a job at a bank near the university. He had met a girl, and decided to live up there. The first time his now-employed son called again for "John Smith", my cousin told the operator, "Tell him that Mr. Smith is dead," and hung up the phone.
