Hypernym of "invoice" and "quote"? [duplicate]
Solution 1:
With respect, you don't actually want a synonym, you want an abstraction that encompasses the general case. You say as much yourself when you talk about a "base class".
So why not look at what is common in these three things?
Each of them is a communication of information about an order, between two or more parties. Each of them will have a date, a sender, an order reference, and one or more recipients.
Sounds awfully like we are talking about a letter. Or more generally, a communication. Or maybe correspondence.
As a programmer, I'd probably go for something like order-correspondence. Then, when I realise that I also need a class for receipt I've got a ready-made base class.
On the other hand, given such a problem, I'd probably go back to the design board and have a good think about what data I have to deal with, and for what purposes, and hope that having a serious think about the design would lead me naturally to the identification of good entity names.
In other words, if the names aren't obvious, the design probably needs more thought.
Solution 2:
Though we can see relations between these three, I doubt you'll find a satisfying synonym to encompass the meaning of all since, similarities aside, they actually do stand for quite different things.
The closest I could posit might be receipt, since each of these have the same property of being received by the person going through the order process.
So, in terms of programming a base class, this could make sense, but I guess we might need more information and a different location to discuss this aspect in much more detail.