The XSD file for XML mappings (http://www.doctrine-project.org/schemas/odm/doctrine-mongo-mapping.xsd) appears to be incomplete:

• Only document is allowed as root tag, not mapped-superclass or embedded-document
• The name attribute for the document tag is not allowed according to the XSD file
• The fieldName, index and unique attributes for the field tag is not allowed according to the XSD file

These are the problems I discovered at the moment, I haven't yet checked for more problems. The XSD file probably needs a bigger update.

Attached is a patch file that adds the missing attributes, I haven't dug into Doctrine enough to create the mapped-superclass or embedded-document tags.