<grammar xmlns="http://relaxng.org/ns/structure/1.0">

<start>

<element name="purls">

<oneOrMore>

<element name="purl">

<attribute name="id"/>

<attribute name="type"/>

<optional>

<element name="maintainers">

<interleave>

<zeroOrMore>

<element name="uid">

<text/>

</element>

</zeroOrMore>

<zeroOrMore>

<element name="gid">

<text/>

</element>

</zeroOrMore>

</interleave>

</element>

</optional>

<optional>

<choice>

<element name="target">

<attribute name="url"/>

</element>

<element name="seealso">

<attribute name="url"/>

</element>

<element name="basepurl">

<attribute name="path"/>

</element>

</choice>

</optional>

</element>

</oneOrMore>

</element>

</start>

</grammar>