What the Heck is the "Main Domain"

I’m on a mission of archiving and letting go of a fleet of domains. In my account, an old obscure one that I definitely do not need is indicated as my “main domain” https://secretrevolution.us - maybe that was the very first one I set up?

It seems to be a parent of some sorts to all my other domains. Can this be changed? What would happen if I let the domain registration lapse?

It’s like one of my worst sites! And I have no need for it.

cPanel has a concept of a “primary domain” which is essentially the domain you signed up for you account with. It doesn’t really hurt anything if you don’t use that domain, or don’t keep it registered, but if you reach out to our support if you’d like it changed!