<test-case name="qischema042" xmlns="http://www.w3.org/2010/09/qt-fots-catalog">
      <description>import a schema in three parts, one of them non-existent. This test relies on the product under test
        (and/or the test driver) respecting relative URIs as schema location hints. The URIs are relative to this
        test catalog file.</description>
      <created by="Michael Kay" on="2006-11-14"/>
      <dependency type="spec" value="XQ10+"/>
      <dependency type="feature" value="schema-location-hint"/>
      <test><![CDATA[
        declare default function namespace "qischema0042.uri"; 
        import schema default element namespace "qischema0042.uri" 
                at "SchemaImport/qischema042.xsd", "SchemaImport/qischema042a.xsd", "SchemaImport/qischema042-non-existent.xsd"; 
        <a>{hatsize(5), bighatsize(8), tinyhatsize(4)}</a>]]></test>
      <result>
         <assert-xml><![CDATA[<a xmlns="qischema0042.uri">5 8 4</a>]]></assert-xml>
      </result>
   </test-case>

XQ30 says:

"The URILiterals that follow the at keyword are optional location hints, and can be interpreted or disregarded in an implementation-dependent way. Multiple location hints might be used to indicate more than one possible place to look for the schema or multiple physical resources to be assembled to form the schema."

An implementation might decide to raise an error upon encountering the non-existent location "SchemaImport/qischema042-non-existent.xsd".