When I worked in New York City back in the early 70s, I used to witness at regular intervals a discussion of what constituted "regular coffee".

You must understand that in NYC speed is very important: when you enter a deli or other purveyor of comestibles and potables, you are expected to bark out your order without hesitation or thought, and you expect in return rapid service in a small brown bag.

So, it would go like this:

Athenian Stranger: I went into so-and-so's and asked for regular coffee, and what do you think they gave me?

Interlocutor A: One cream, two sugars?

Athenian Stranger: That's not regular coffee! That's what they gave me, but that's not regular coffee! Regular coffee is one milk, no sugar.

Interlocutor B: What are you talking about? What you described is "slim, no sweet". Regular coffee is black, no sugar.

Interlocutor A: No, that's "black, no sugar"...

And so it would go. Of course, my contribution* was always discarded out of hand.

*Regular coffee is not a technical term; what it refers to depends on where you go.