OptionalbackgroundOptionalcolorThe id of the color scheme offered for the map's colors. Without it, the default scheme.
OptionallabelsHow the labels of markers are shown. Those of the background map are settings of the background.
OptionallegendA legend, defined by the author, not generated from the elements.
OptionaltitleThe title of the map, e.g. for the list of maps, the title of the page and file names.
OptionalviewerWhat a shared or embedded map shows over it, and where: the search, the zoom buttons, the legend.
The background map. Without it, the map has the default one: the vector map of OpenStreetMap in the theme "colorful", see
BACKGROUND_DEFAULTS.