sequence minOccurs="0"

<complexType name="withOptionalSequence">
  <annotation>
   <documentation>
    This complex type defines
    the sequence of subsequences: the first
    subsequence is optional while the
    second one is mandatory.
    Note that subelements of both subsequences
    are optional.
   </documentation>
  </annotation>
  <sequence>
   <sequence minOccurs="0">
    <element ref="e1" minOccurs="0"/>
    <element ref="e2" minOccurs="0"/>
   </sequence>
   <sequence>
    <element ref="e3" minOccurs="0"/>
    <element ref="e4" minOccurs="0"/>
   </sequence>
  </sequence>
 </complexType>

Plz read the Above code, i want to know is it necessary to specify the
<sequence minOccurs="0"> because the elements are also optinal under
this sequence.

Lax