Prohibited attributes in an attributeGroup

This comment is regarding having prohibited attributes in an
attributeGroup.

 

Base Type:

 

<xsd:complexType name="base">

      <xsd:attribute name="a" />

</xsd:complexType>

 

Derived Type:

 

<xsd:complexType name="derived">

  <xsd:complexContent>

    <xsd:restriction base="base">

      <xsd:attributeGroup ref="attG"/>

    </xsd:restriction>

  </xsd:complexContent>

</xsd:complexType>

 

<xsd:attributeGroup name="attG">

 <xsd:attribute name="a" use="prohibited"/> </xsd:attributeGroup>

 

Should the complex type "derived" still have attribute "a"? From the
spec, it seems that it would allow attribute "a", since the
attribute-uses of the attributeGroup "attG" does not contain "a".

 

It seems that having a prohibited attribute in an attributeGroup is
useless and does nothing, and it could be argued that such attributes
should be disallowed from attribute groups.