User Configuration > Administrative Templates > Microsoft Word 2016 > Word Options > Security > Trust Center > File Block Settings
User
HKCU\software\policies\microsoft\office\16.0\word\security\fileblock
This policy setting allows you to determine if users can open, view, or edit Word files. If you enable this policy setting, you can set one of these options: - Blocked files are not opened - Blocked files open in Protected View and can not be edited - Blocked files open in Protected View and can be edited If you disable or do not configure this policy setting, users will be able to open blocked files, but not edit them.