Welll, it can't be valid if memo.dtd is an empty file, because you
don't have <!ELEMENT memo .. > anywhere. But yes, 5.1 suggests the
attribute default shouldn't be used.
>The receiver has no way of knowing that this case has occured if it uses a
>"standard parser"
If the sender is stupid enough to send something like this to a
non-validating parser, he gets what he deserves. If it's a validating
parser, then of course the emptiness of memo.dtd will be detected.
> (since XML's semantics are, for the moment at least,
>imprecisely specified, I only know what that means intuitively ... SAX,
>Lark, Expat, etc. would not give you enough information to detect this
>case).
Huh?
>This to me suggest that applications cannot trust the SDD and it must
>therefore be presumed to be meaningless.
You do raise a good question; it would seem that standalone='true'
*ought* to mean that the rule of 5.1 about the effect of
external PE refs could be ignored. Hmmmm -Tim