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.