User Configuration > Administrative Templates > Microsoft Word 2016 > Word Options > Save
User
HKCU\software\policies\microsoft\office\16.0\word\options
This policy setting allows you to specify the default compatibility mode when creating new files in Word. There are four modes: 1. Word 2003: This mode disables features in Word that are not compatible with Word 2003. 2. Word 2007: This mode disables features in Word that are not compatible with Word 2007. 3. Word 2010: This mode disables features in Word that are not compatible with Word 2010. 4. Full functionality mode: This mode ensures that all new features remain enabled. This is the default setting for Word. Note: Not all file formats support all four Compatibility Modes. Open XML file formats such as .docx and .dotx, support all four modes.