SilverBullet has a few “special pages.” The convention is to always use ALL CAPS for these page names. Generally the format of these pages is that they can contain arbitrary text, but embedded in them is some sort of fenced code block (triple backtick blocks) that encode something special. What _exactly_ depends on the page.
All special pages except [[SETTINGS]] are optional: if they don’t exist, well, they don’t do anything.
Here are the current list of “special pages” known to humankind: