Where 2 people link up but arent in a
relationship, however, if you and that person want to be in a
relationship in a couple of years time, you both make a promise with eachother to be in a relationship in the future. Kinda like a promise ring but you start with a friendship and then promise to go into a relationship with them in the future.
This is mostly for people doing
long distance relationship but can also be for normal relationship aswell.