From: Laird Nelson <ljnelson_at_gmail.com>
Date: Tue, 29 Oct 2013 08:09:44 -0700
The persistence.xml schema has the following towards the top of the file:
<xsd:documentation><![CDATA[
This is the XML Schema for the persistence object/relational
mapping file.
The file may be named "META-INF/orm.xml" in the persistence
archive or it may be named some other name which would be
used to locate the file as resource on the classpath.
Object/relational mapping files must indicate the object/relational
mapping file schema by using the persistence namespace: