marks 

indicates whether or not punctation marks have been retained as content
within the text.

Attribute Information

Source 

<xs:attribute name="marks">
  <xs:annotation>
    <xs:documentation>indicates whether or not punctation marks have been retained as content within the text.</xs:documentation>
  </xs:annotation>
  <xs:simpleType>
    <xs:restriction base="xs:token">
      <xs:enumeration value="none">
        <xs:annotation>
          <xs:documentation>no punctuation marks have been retained</xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value="some">
        <xs:annotation>
          <xs:documentation>some punctuation marks have been retained</xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value="all">
        <xs:annotation>
          <xs:documentation>all punctuation marks have been retained</xs:documentation>
        </xs:annotation>
      </xs:enumeration>
    </xs:restriction>
  </xs:simpleType>
</xs:attribute>

Sample