I'm the author of the new BNF, not that it matters. The main features of this
new BNF are:
1) It emphasizes that boundary delimiters start at the beginning of a line and
end with a CRLF.
2) It eliminates the silly-appearing extra CRLF that must occur when there is
no prelude.
The whole point of the exercise was to redefine delimiter and close-delimiter
to meet those goals, and adjust the rest of the BNF appropriately. I don't
particularly understand why it is awkward, but it's a matter of personal taste
I guess.
-- Mark --