Reference to a meteorological phenomena or property defined outside WOML.A MeteorologicalSymbol is only identified by a reference to a catalog ("definitionReference")
The attribute gml:id supports provision of a handle for the XML element representing a GML Object. Its use is mandatory for all GML objects. It is of XML type ID, so is constrained to be unique in the XML document within which it occurs.
Source
<complexType name="MeteorologicalSymbolType"><annotation><documentation>Reference to a meteorological phenomena or property defined outside WOML. A MeteorologicalSymbol is only identified by a reference to a catalog ("definitionReference")</documentation></annotation><complexContent><extension base="gml:AbstractGMLType"><sequence><element name="definitionReference" type="womlcore:catalogReferenceType" minOccurs="0" maxOccurs="unbounded"/><element name="localizedSymbolName" type="womlcore:shortLocalizedStringType" minOccurs="0" maxOccurs="unbounded"/></sequence></extension></complexContent></complexType>