The phrase "seat save" is a phrase used by one who wishes to leave an occupied seat with the intention of returning to said seat. The rules of using the phrase are as follows-

1.) you must call "seat save" within 3 feet of the seat.

2.) you just designate the seat

3.) you cannot leave a saved seat for longer than 5 minutes

If these rules are not used, the seat is unsafe and may be taken.