A designation of (map) after the domain name indicates that the domain only specializes map
elements; a designation of (topic) indicates that the domain specializes elements that are only
available in topic or that it can only be used in topics. A
designation of (map/topic) indicates that the domain specializes elements that are common to
both maps and topics, so could be used in either even if it is generally intended for one or the
other. Attribute domains can always be used in both topics and
maps.