Require trusted publisher signatures for macros that are always loaded

This policy setting controls signature requirements for macros that are automatically loaded when Office applications start.

Macros that are always loaded include VBA add-ins and templates that load automatically: Excel add-ins (xla/xlam), PowerPoint add-ins (ppa/ppam), Access add-ins (accda/mda), and Word templates (dot/dotm).

If you enable this policy setting:
- Unsigned macros that are always loaded are silently disabled and don't load.
- Signed but untrusted macros that are always loaded display a red Message Bar with no option for users to enable them for the current session.
- Macros signed by a trusted publisher are allowed to always load.

If you disable or don't configure this policy setting, macros that are always on can load without requiring trusted publisher signatures.