vnd.error+xml

Collection.xml

<?xml version="1.0"?>
<resource>
  <total>2</total>
  <resource rel="errors" logref="50">
    <link rel="help" href="http://.../"/>
    <message>"username" field validation failed</message>
  </resource>
  <resource rel="errors" logref="55">
    <link rel="help" href="http://.../"/>
    <message>"postcode" field validation failed</message>
  </resource>
</resource>

Embedded.xml

<?xml version="1.0"?>
<resource logref="42">
  <link rel="describes" href="http://path.to/describes"/>
  <link rel="help" href="http://path.to/help"/>
  <link rel="about" href="http://path.to/user/resource/1"/>
  <message>Validation failed</message>
  <resource rel="errors">
    <link rel="about" href="http://path.to/user/resource/1"/>
    <message>Username must contain at least three characters</message>
    <path>/username</path>
  </resource>
</resource>