OGC Web Map Context Document (.cml;.ccml;*.xml)

A Web Map Context (WMC) document contains references to one or more OGC Web Map Service layers.

Data in WMC documents is served in layered raster images, rather than as a single raster image.

For example, one layer could represent cities, another layer could represent province outlines and so on. Each raster layer can have transparent values, so that layers underneath them are not obscured.