SharePoint 2010 Comments within Content Types

Recently I came across a content type which had comments within the field references. 

<Elements xmlns="http://schemas.microsoft.com/sharepoint/">
  <ContentType ID="0x01005B46F6F81C7447289D88DC03731379DF" Name="Content Type Name" Description="My Content Type" Group="My Content Types">
    <FieldRefs>
      <FieldRef ID="{81d3f215-b0e8-47d0-b9fc-42687f849c85}" Name="Field1" DisplayName="Field 1" />
      <!--<FieldRef ID="{ca10fe52-eee8-4e0a-bfc5-7b77db491dc5}" Name="Field2" DisplayName="Field 2" />-->
      <FieldRef ID="{798458ED-612F-45BE-AF77-5AB09A769270}" Name="Field2" DisplayName="Field 2" />
    </FieldRefs>
  </ContentType>
</Elements>

The content type deployed as expected, however, when you created a content type which inherited from this content type only the fields above the comment are pulled through into the inherited content type.