User Configuration > Administrative Templates > Microsoft Word 2016 > File Tab > Check Accessibility
User
HKCU\software\policies\microsoft\office\16.0\word\accchecker
This policy setting prevents the Accessibility Checker from checking to ensure that headings in a document are succinct. If you enable this policy setting, the Accessibility Checker will be prevented from checking to ensure that headings in a document are succinct. If you disable or do not configure this policy setting, document headings will be checked for length and any issues will appear in the Accessibility Checker.