The SquareCharacteristicDefinitionType defines information that can be common to more than one square characteristic. This is the length of a side of a square.
The id attribute is the QIF id of the characteristic, used for referencing.
Source
<xs:complexType name="SquareCharacteristicDefinitionType"><xs:annotation><xs:documentation>The SquareCharacteristicDefinitionType defines information that can be common to more than one square characteristic. This is the length of a side of a square.</xs:documentation><xs:documentation>ASME Y14.5 - 2009 Section 3.3.16</xs:documentation></xs:annotation><xs:complexContent><xs:extension base="LinearCharacteristicDefinitionBaseType"/></xs:complexContent></xs:complexType>