HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\excel\security\trusted documents

Turn off trusted documents
- HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\excel\security\trusted documents\disabletrusteddocuments
Set maximum number of trust records to preserve
- HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\excel\security\trusted documents\maxpreservetrusteddocuments
Set maximum number of trusted documents
- HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\excel\security\trusted documents\maxtrusteddocuments
Turn off Trusted Documents on the network
- HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\excel\security\trusted documents\disablenetworktrusteddocuments