jade comb

An owned item or object left either intentionally or accidentally in the posession of another person (typically with one whom shares affection) ensuring the promise that they shall meet again. This may either be a special promise or a burden, depending on which person said item was left with.

Bro: "What are you looking for?"
Homie: "Just doing a quick once-over through your apartment. I'm leaving for Vegas and don't want to leave a jade comb"

"Oh, I left my hat? Keep it for now, it's my jade comb."

Take this necklace, it will be a jade comb promising I will meet you here again this time next year.