Note: `PackageArchive::readPackageInfo()` also handles `readme` and
`license` which are also missing in the `package.xsd` file.
</xs:simpleContent>
</xs:complexType>
</xs:element>
+ <xs:element name="packageurl" type="xs:anyURI" minOccurs="0" maxOccurs="1" />
<xs:element name="standalone" type="woltlab_boolean" minOccurs="0" maxOccurs="1" />
<xs:element name="isunique" type="woltlab_boolean" minOccurs="0" maxOccurs="1" />
<xs:element name="version" type="woltlab_varchar" minOccurs="1" maxOccurs="1" />