Every knob catalogue in the SDK and its plugins uses this vocabulary, so a UI or an agent that learned one catalogue can read the other.
toggle: true/false, e.g. whether an overlay is drawn.factor: a multiplier over what the style already does (1 = unchanged).number: an absolute number with a range.offset: an [x, y] displacement on screen, x to the right and y down, each within the
knob's range. The description gives the unit.color: a CSS colour string.enum: one of the knob's options.enums: a list of the knob's options, e.g. the categories a filter shows. The description
says when the order matters.colors: a list of colours, each a CSS colour string or one of the knob's options, which
are names the module resolves to colours, such as styling knob ids. An empty list is the knob's default.image: the id of an image in the loaded style's sprite, e.g. poi-toll_plaza.text: any string, e.g. the label written after a distance.
The kind of value a display knob takes.