The OGC Web Coverage Service (WCS) supports electronic retrieval of geospatial data as coverages - that is, digital geospatial information representing space/time-varying phe-nomena. This document specifies the WCS core; every implementation of a WCS shall adhere to this standard. This standard thus defines only basic requirements. Extensions to the core will define extensions to meet additional requirements, such as the response encoding. Indeed, additional extensions are required in order to completely specify a WCS for implementation.