Length 

nn for pixels or nn% for percentage length

Simple Type Information

Used By

Attributes applet/@height, applet/@width, cellhalign/@charoff, hr/@width, iframe/@height, iframe/@width, img/@border, img/@height, img/@width, object/@height, object/@width, table/@cellpadding, table/@cellspacing, table/@width, td/@height, td/@width, th/@height, th/@width

Source 

<xs:simpleType name="Length">
  <xs:annotation>
    <xs:documentation>nn for pixels or nn% for percentage length</xs:documentation>
  </xs:annotation>
  <xs:restriction base="xs:string">
    <xs:pattern value="[-+]?(\d+|\d+(\.\d+)?%)"/>
  </xs:restriction>
</xs:simpleType>