MOXy @XmlPath expressions, are they supported?

Are XPath expressions such as the following supported in MOXy?

field[XMLtag!='identifier']

Basically I've got XML like this

<demographics>
  <field>
    <value>12345</value>
    <XMLtag>identifier</XMLtag>
  </field>
  <field>
    <value>somename</value>
    <XMLtag>name</XMLtag>
  </field>
</demographics>

I'm trying to get a List to populate with but exclude the field which is for identifier.

This will work but gives me all field elements (2) in the List ( correctly )

@XmlElement( name = "field" )
public List<Field2> fieldList;

This will not, I get an empty List

@XmlPath( "field[XMLtag!='identifier']" )
public List<Field2> fieldList;

Should the above work, or are expressions like that not supported by MOXy? I can't seem to find any information about them.

I've not included my Field2 class as it's very simple and obviously works okay as I can unmarshall to list if using @XmlElement annotation. Let me know if you'd like to see it.