This page attempts to define what "on topic" means, both for this wiki and for a particular page.
First of all, the topic for this wiki is Blackbox, so most of the contents should be about Blackbox and stuff related to Blackbox. We make some exceptions for contents about this wiki and wikis in general (how to use it and so on).
Every page should contain things directly related to its title. If a page gets too big and getting sidetracked becomes common, perhaps it's time to split it in smaller pages.