labelControl

In the object model this is RibbonLabel
A labelControl is a textual element and has no actions.
It is often used to provide header to columns of related buttons.
A label must appear in a group.

<customUI xmlns="http://schemas.microsoft.com/office/2009/07/customui"> 
  <ribbon startFromScratch="true">  
    <tabs> 
      <tab id="CustomTab" label="My Tab"> 
        <group id="Group1" label="Group 1"> 
          <labelControl id="MyLabel1" 
                        label="Label 1" /> 
          <labelControl id="MyLabel2" 
                        label="Label 2" /> 
        </group> 
        <group id="Group2" label="Group 2"> 
          <labelControl id="MyLabel3" 
                        label="Very Long Label" /> 
        </group> 
      </tab> 
    </tabs> 
  </ribbon> 
</customUI> 

Attributes (properties)

Callbacks (run-time)

' VBA
Public Sub Label_OnGetLabel( _ 
   ByRef control As Office.IRibbonControl, _ 
   ByRef Label As Variant) 

   Label = "my dynamic label" 
End Sub 

' C# Equivalent
string Label_OnGetLabel( 
   Microsoft.Office.Core.IRibbonControl control) 
{ 
}