ietf-nntp newsgroup production

[Chin Chee-Kai]

The "newsgroup" production under Section 13 doesn't seem to be
sufficiently refined;  it allows newsgroup references such as
"...." to be admissible when a more specific production set 
could rule out these occurences as valid references.

Below is a suggested change of 
    1. the "newsgroup" production,
    2. "augument" spelling correction pointed out previously,
    3. and the consensus-pending removal of "DEBUG".

Cheers,
CK

Lines marked with a beginning "+" are changes suggested.
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          13.  Augmented BNF[9] Syntax for NNTP Commands

          [..........]
+         The conventions as defined in RFC822 are used.  In addition, the
+         notation "\", when used in the production rules, denotes exclusion.

+           argument = parameter ; excluding sequence ".."
+           ;;; original production ::  augument = parameter ; excluding sequence ".."

            [..........]

            command = article-command /
               body-command /
+                   ;;;       debug-command /   ; pending consensus to remove this
               date-command /
               [..........]
+           ;;; debug-command = "DEBUG" 1*WSP ("ON"/"OFF"/"ACK") *WSP CRLF
+                   ; pending consensus to remove this

            [..........]

+           newsgroup = newsgroup-segment *(DOT newsgroup-segment)
+           newsgroup-segment = parameter \ DOT
+           DOT = %x2E
+                   ;;; parameter excluding DOT
+           ;;; original production ::  newsgroup = parameter
+           ;;;         which allowed newsgroups like "...."
+           ;;;         because DOT was a parameter
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