Years ago, I remember reading a novel (I think it was The Three Musketeers, maybe?) that had a few paragraphs inside parenthesis, and it followed the convention for a multiple paragraph quotation:
(Paragraph 1.
(Paragraph 2.
(Paragraph 3.)
So I'm curious, is this actually a convention? Google search seems to be failing me here.
I'm asking entirely out of curiosity, by the way. I don't currently have any intention of using a multiple paragraph parenthetical in my own writing.