On Fri, 18 May 2007, John C Klensin wrote: > On Friday, 18 May, 2007 09:00 +0100 Tony Finch <dot@xxxxxxxx> > wrote: > > > > NTWSP = [CRLF] 1*WSP ; non-trailing white space > > Sure. Except that much, if not most, of our textual > descriptions of these protocols describes lines, and line-like, > constructions as _ending_ in CRLF. Moving to "starting in > CRLF" creates a conceptual difference between prose definition > and formal syntax, which strikes me as a bad idea. Don't do that then. The suggestion I made above was for a no-trailing- whitespace variant of 2822's FWS, and as such it would be used in a grammar inside a logical line, not at either end. You seem to be inventing problems that might occur in badly-designed grammars, and as such these are bugs in the grammars and not due to limitations of ABNF (which, after all, is equivalent to any other notation for describing context-free grammars). > Of course, in the above, since [CRLF] is optional, "1*WSP" alone > satisfies the production as written and still does not prevent > <CRLF> space space space > <CRLF> Um, no, because WSP = SP / HTAB Tony. -- f.a.n.finch <dot@xxxxxxxx> http://dotat.at/ SOUTHEAST ICELAND: CYCLONIC, BECOMING NORTHERLY GALE 8 OR SEVERE GALE 9, DECREASING 6 OR 7. ROUGH OR VERY ROUGH, OCCASIONALLY HIGH. SHOWERS. MODERATE OR GOOD. _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf