XML for install/uninstall list custom action (button)

<CommandUIExtension>
  <CommandUIDefinitions>
    <CommandUIDefinition
      Location="Ribbon.Documents.Manage.Controls._children">
      <Button
        Id="Ribbon.Documents.Manage.MoveToArchive"
        Sequence="100"
        TemplateAlias="o1"
        Image16by16="/_layouts/nova.bhb.policies.archive/Images/archive16.png"
        Image32by32="/_layouts/nova.bhb.policies.archive/Images/archive32.png"
        Command="COMMANDGUID"
        LabelText="Move to the Archive" />
    </CommandUIDefinition>
  </CommandUIDefinitions>
  <CommandUIHandlers>
    <CommandUIHandler
      Command ="COMMANDGUID"
      CommandAction="javascript:NovaBhbMta.ArchiveSelection();"
      EnabledScript="javascript:NovaBhbMta.CheckSelection();"
      />
  </CommandUIHandlers>
</CommandUIExtension>