: SY_ReferenceParameterhttp://def.isotc211.org/iso19117/2012/SymbolParameterExtension# Create a prefix for http://def.isotc211.org/iso19117/2012/SymbolParameterExtension# Hit Enter to save Double click to create a prefix | : constrainthttp://def.isotc211.org/iso19150/-2/2012/base# Create a prefix for http://def.isotc211.org/iso19150/-2/2012/base# Hit Enter to save Double click to create a prefix | type.conformsTo(SY_Symbol) |