User Configuration > Administrative Templates > Microsoft Office 2016 > Manage Restricted Permissions
User
HKCU\software\policies\microsoft\office\16.0\common\drm
Provide the path to a folder with document, spreadsheet, and presentation files to be used as templates for a unencrypted wrapper for files with rights-managed content received by users with older versions of Office. Office includes plain-text wrapper documents that notify users about a rights-managed document in certain circumstances. If the user's application cannot recognize a document that includes rights-management, the user receives the wrapper document with information such as instructions for downloading a Rights Management Add-on for Windows Internet Explorer. You can provide a folder with customized templates for Office to use for these plain-text wrappers by using this setting to specify a URL to a folder.