What is a Multiple Domain (UCC) SSL certificate?
A Unified Communications Certificate (UCC) is an SSL certificate that protects multiple domains and subdomains. UCC certificates can be used on GoDaddy hosting products to protect multiple websites.
They’re ideal for Microsoft® Exchange Server 2013, Exchange Server 2016 and Microsoft Live® Communications Server.
While the site seal and certificate "Issued To" information will only list show the primary domain name, but all of your domains and subdomains will be listed on the same certificate. If you do not want your sites to appear connected to each other, you shouldn't use this type of certificate.
Note: You cannot upgrade a UCC to include more names. If you are using all of the slots available in your current UCC certificate, and you need to cover another domain, you'll need to purchase a new certificate to add another domain name.