Yes, I can. Paper is the best form of asynchronous communication, requiring neither electricity or complex authentication schemes. By placing a piece of paper on the side of another person’s desk as quietly as possible, one would ensure that the person will be alerted to a necessary matter when they have the time to inspect their physical inbox.
It also indicates the matter is important enough for the original person to walk up and deliver a note.
Funny - one of our teammates used to do this at a previous company. We built in a similar function for remote workers with a Slack integration. It sends a little message with pre-formatted responses that indicates you'd like to talk on Tandem.