isSI 

<h:div class="summary">indicates whether a unit is an SI or derived SI unit.</h:div>
<h:div class="description">required on SI unit elements with value 'true'. Optional on other units with attribute 'false'. A unitList should contain either SI units or non-SI units but not both.</h:div>

Attribute Information

Used By

Attribute Group isSI

Source 

<xsd:attribute name="isSI" id="att.isSI" type="xsd:boolean">
  <xsd:annotation>
    <xsd:documentation>
      <h:div class="summary">indicates whether a unit is an SI or derived SI unit.</h:div>
      <h:div class="description">required on SI unit elements with value 'true'. Optional on other units with attribute 'false'. A unitList should contain either SI units or non-SI units but not both.</h:div>
    </xsd:documentation>
  </xsd:annotation>
</xsd:attribute>

Sample