Re: Non-Validating XML Parsers: Requirements

John Cowan (cowan@locke.ccil.org)
Tue, 04 Aug 1998 14:15:29 -0400


Michael Kay wrote:

> Thanks for the reference. I've read it now. I'm relieved to
> discover it does not recommend or assign a meaning to the
> phrase "MAY NOT".

You are correct. Mea culpa.

> Wherever "MAY NOT" appears in a (so-called) spec, it either
> means "MUST NOT" or it means "MAY OR MAY NOT", which is a
> synonym for "MAY", and which, as I remarked earlier, is
> formally equivalent to omitting the sentence.

I meant the latter: MAY or may not.

> >
> >> I don't much like "may" either. Everything is permitted
> >> unless the specification prohibits it, a sentence whose
> main
> >> verb is "may" therefore says nothing.

[snip my earlier, flippant response]

Seriously, though, what I wrote was not really a spec, but a
clarification of an existing spec. In that case, MAY is useful,
for it expresses behavior on which the client cannot depend,
but which may be provided.

-- 
John Cowan	http://www.ccil.org/~cowan		cowan@ccil.org
	You tollerday donsk?  N.  You tolkatiff scowegian?  Nn.
	You spigotty anglease?  Nnn.  You phonio saxo?  Nnnn.
		Clear all so!  'Tis a Jute.... (Finnegans Wake 16.5)