'Single domain' and 'multi domain' HTTPS certificates are the same thing

Author here. Short version: 'single' and 'multi domain' HTTPS certificates have been the same thing for about a decade. The only reason they're referred to as separate products are commercial:

- old systems in a stagnant industry that haven't been updated

- the chance to create arbitrary product distinctions

Pretty much everything in the article is referenced in RFC 2818 (HTTP Over TLS), the Baseline Requirements, and RFC 6125 (x509 for TLS) but if there's anything missing let me know.

I think that many newer vendors of certificates are following this model. Let's Encrypt and AWS Certificate Manager both simply have certificates with names. One name, two names, 50 names, still just a "certificate".

(Disclosure, I work with AWS)