reserverule
nounUK /rɪˈzɜːv ruːl/
US /rɪˈzɜːrv ruːl/
A reserve rule is a rule that saves something for later use.
The reserve rule says we keep some water for the dry days.
OTHER MEANINGS
2. A rule that keeps a player ready to play if needed.
The coach used a reserve rule to keep two players on the bench.
3. A rule that sets aside part of something for emergencies.
The reserve rule keeps extra money in the bank for hard times.
4. A rule that holds a seat or place for someone later.
The reserve rule let us save a table for our friends.