Tab

Sample Ribbon XML file:

<customUI xmlns="http://schemas.microsoft.com/office/2006/01/customui">
   <ribbon startFromScratch="false">
      <tabs>
          <tab id="MyTab1" 
               label="My Tab1">
          </tab>
          <tab id="MyTab2" 
               label="My Tab2">
          </tab>
          <tab id="MyTab3" 
               label="My Tab3">
          </tab>
      </tabs>
   </ribbon>
</customUI>

Attributes: id, idMso, idQ, insertAfterMso, insertAfterQ, insertBeforeMso,
                 insertBeforeQ, keytip, label, tag, visible

 Callbacks: getKeytip, getLabel, getVisible

You can find this sample in Sample DB 1