<notation> and namespaces

Let say we have the following: 
  <notation name="jpeg" SYSTEM="pw.exe"/>

  <simpleType name="myNotation">
   <restriction base="NOTATION">
     <enumeration value="jpeg"/>
   </restriction>
  </simpleType>
 
  <element name="picture">
    <complexType>
      <complexContent>
        <extension base="xs:binary">
          <attribute name="pictype" type="myNotation"/>
        </extension>
      </complexContent>
    </complexType>
  </element>
 
Everything works fine in above case.
However, is it possible for user to import schema with <notation>
definitions? In other words, is it possible to have 2 notation
declarations, with same name but from a different namespace? 

If yes, how do we specify "value" on enumeration?  
Enumeration value must be string (according to datatypes), but in fact
we need QNAME to differentiate between notations in different
namespaces.

Am I missing something? 

Thank you,
Elena