A "post it note" is the signal of lift off in 215. After attending club 307 if you bring a bitch, hoe, or otherwise incapacitated female to the room, a "post it note" is placed (smoothly)(like a gangsta') on the outside of the door. This is to signal that you are currently getting ass.
When a woman forgets to do or get something, the man waits till she falls asleep, and then proceeds to write what she forgot on a piece of paper. He then jerks off onto her face/forehead and presses the note, facing her eyes, onto her face.
When defacing a public restroom stall by smearing one's shit on the interior stalls wall with one's own underwear, leaving the underwear on the interior of the door, face high, held up by the drying shit, for the next person.
When I went to the bathroom at Target, I was surprised that someone left a smelly Post-It Note Especial hanging in the door for me.