A Schema for a Document that Uses the Default Namespace

• The elementFormDefault attribute must have the value qualified to indicate that the locally defined elements -- i.e., TITLE, PHOTO, COMPOSER, PRODUCER, PUBLISHER, YEAR, and ARTIST -- are qualified.

• Globally defined elements such as SONG are always qualified by the target namespace

• The default value of elementFormDefault is unqualified. This is exactly backwards from what it should be.

• The default value of attributeFormDefault is unqualified. This is correct.

• This mess was caused by an misguided attempt to make local elements and attributes equivalent.

• Simplest approach: either don't use namespaces at all or make sure all elements are namespace qualified and set elementFormDefualt="qualified"

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  xmlns="http://ibiblio.org/xml/namespace/song"
  targetNamespace="http://ibiblio.org/xml/namespace/song"
  elementFormDefault="qualified"
  attributeFormDefault="unqualified"
>
 
  <xsd:element name="SONG" type="SongType"/>

  <xsd:complexType name="SongType">
    <xsd:sequence>
      <xsd:element name="TITLE" type="xsd:string"/>
      <xsd:element name="PHOTO" type="PhotoType"  
        minOccurs="0"/>
      <xsd:element name="COMPOSER"  type="xsd:string" 
        maxOccurs="unbounded"/>
      <xsd:element name="PRODUCER"  type="xsd:string" 
        minOccurs="0" maxOccurs="unbounded"/>
      <xsd:element name="PUBLISHER" type="xsd:string" 
        minOccurs="0"/>    
      <xsd:element name="YEAR" type="xsd:gYear"/>
      <xsd:element name="ARTIST" type="xsd:string" 
        minOccurs="0" maxOccurs="unbounded"/>
    </xsd:sequence>
  </xsd:complexType>

  <xsd:complexType name="PhotoType">
    <xsd:complexContent>
       <xsd:restriction base="xsd:anyType">
         <xsd:attribute name="ALT"    type="xsd:string"/>
         <xsd:attribute name="WIDTH"  type="xsd:nonNegativeInteger"/>
         <xsd:attribute name="HEIGHT" type="xsd:nonNegativeInteger"/> 
      </xsd:restriction>
    </xsd:complexContent>
  </xsd:complexType>
  
</xsd:schema>