The IoT Security Rating, which is based on UL’s IoT Security Top 20 Design Principles, aims to serve two purposes:
1) Help manufacturers and developers improve the security posture of their solutions by leveraging proven security best practices
2) Rate the security posture of IoT solutions in order to make security more transparent and accessible to consumers.
https://ims.ul.com/IoT-security-rating

I wish these logos had more specifics, like what boot security technologies are available.