Ask HN: Ever seen two companies share a domain?

When I was in college I was helping a small business set up a website. The business's name was long. The obvious .com domain name, while available, would have been unwieldy to type in an email. The owner often abbreviated the company's name with three letters, and wondered if we could have the three-letter domain ".com." Of course, that domain was already in use, to which he asked, "can we have it too?"

I asked what he wanted people to see when they typed in the web address. On the one hand, every millennial has stories of explaining how the internet works to impatient, older people. He was especially scandalized (and I don't think he fully believed me) when he learned what registered domain names generally cost. Remembering that conversation now has me thinking... the internet is a weird place full of ad-hoc cooperative arrangements. In the age of JSON-LD schemas, well-known URLs, and EXTERNAL SENDER warnings, perhaps no corporation with a significant digital strategy will stomach sharing a domain. But do any of you know of examples of domain sharing among smaller firms? Does anybody make it work? How did the arrangement come about?