Settings & keep-time · Rules and safety floors
What do the archive and delete floor settings do?
Short answer: They raise the minimum age for all move rules or all delete rules at once. A floor can only make rules more cautious, never less; set it to 0 to use each rule's own age.
They let you raise the minimum age for a whole group of rules at once, without editing each one. Floor — raise all archive ages to at least applies to move rules; Floor — raise all delete ages to at least applies to delete rules. Both are under Global overrides in Settings → Rules.
A floor can only make rules more cautious: each rule uses whichever is older, its own age or the floor. Set a floor to 0 to turn it off and let each rule's own age stand.