certificate packs
Certificate packs allow Safe Health to fallback to a different SSL certificate for browsers that do not support the latest standards. Certificate packs allow Custom SSL certificates to contain different signature algorithms for the same hostnames listed within the SSL certificate without taking up additional Custom SSL certificate quota for your Safe Health account.
A Certificate Pack is a group of certificates that share the same set of hostnames (i.e. “example.com” and “*.example.com”), but use different signature algorithms.
Relevant links: Managing Custom SSL certificates