This policy setting controls whether Office applications save Information Rights Management (IRM)-enabled files in a format ...

This policy setting controls whether Office applications save Information Rights Management (IRM)--enabled files in a format that allows them to be viewed in Microsoft Internet Explorer with the Windows Rights Management Add-on. The Windows Rights Management Add-on for Internet Explorer provides a way for users who do not use Office 2010 to view, but not alter, files with restricted permissions.
      
If you enable this policy setting, an embedded rights-managed HTML version of the content is saved with each IRM-enabled file, which can be viewed in Internet Explorer using the add-on. This configuration increases the size of rights-managed files, in some cases significantly.

If you disable or do not configure this policy setting, Office applications do not save IRM--enabled files in a format that supports the Windows Rights Management Add-on.