This attribute is only a placeholder so that all the ISM attributes are not shown
in the schemaGuide for every element. If you refer to the documentation of the
attribute group it will say what attributes should be here.
Source
<xs:complexType name="TemporalCoverageType"><xs:annotation><xs:appinfo><mdr:definition>Type used to model the temporalCoverage element.</mdr:definition></xs:appinfo></xs:annotation><xs:sequence><xs:element name="TimePeriod" type="TimePeriodType"/></xs:sequence><xs:attributeGroup ref="ICISM:SecurityAttributesOptionGroup"/></xs:complexType>