The IfThenSurfaceRuleType defines a conditional rule that applies if the feature under consideration is a surface feature. The rule contains an inherited 'if' part and an inherited ThenPoints part. The 'then' part of the rule applies if the 'if' part does not exist or evaluates to true.
The optional name attribute is the name of the rule.
Source
<xs:complexType name="IfThenSurfaceRuleType"><xs:annotation><xs:documentation>The IfThenSurfaceRuleType defines a conditional rule that applies if the feature under consideration is a surface feature. The rule contains an inherited 'if' part and an inherited ThenPoints part. The 'then' part of the rule applies if the 'if' part does not exist or evaluates to true.</xs:documentation></xs:annotation><xs:complexContent><xs:extension base="IfThenFeatureRuleType"/></xs:complexContent></xs:complexType>