ELI5: Explain Like I'm 5

Precancel

A precancel is like stamp that has already been marked before it is used. It is used to save time and make things easier when a lot of letters and packages need to be sent.

Imagine you have a pile of letters that you need to send. Each letter needs a stamp on it, but you don't want to take the time to put the stamp on each letter one-by-one. So instead, you use a special stamp that has already been marked with the post office's name and the value of the stamp.

When you use the precancel stamp, you don't have to worry about putting the stamp on each individual letter. You can just quickly stamp a bunch of letters at once and they are all ready to be sent. This saves a lot of time and makes things easier for everyone.

So, a precancel is like a pre-marked stamp that is used to save time when sending lots of letters and packages.