The page order. The page with the condition must be the last one. The RPG Maker XP checks the pages with conditions backward (first is the last page) and when the event match the conditions the page runs. If you have a page with no condition, this page is ran when checked in RPG Maker XP. If none page match the conditions nothing is ran.
When I says "runs" I mean activates by it trigger condition (Action Button, Player Touch, Autorun, etc...).