Any HTML markup generated by a web content management system should be customizable. This includes everything from the opening html tag to forms. If the system creates tags they should be customizable by the site publisher.
Why? This provides maximum flexibility to the site owner in deploying their desired template and overall design. Sounds like a no-brainer, huh?
You might be surprised how often this can be an issue, particularly with content management systems that are not very mature or have not been updated in a while. It creates many headaches in deploying web site designs and might even prevent the site owner from deploying the best possible design for their needs.
Add this to your list of key things to assess when reviewing web content management system.