Re: Richmail & Idraw

[John C Klensin <KLENSIN@xxxxxxxxxxxxxxx>]

>I've been reading
>about SGML, and I believe that I can change the richmail syntax so that
?it can be viewed as a minimal SGML subtype (although I'm not about to
>actually write the DTD for it).  However, after reading a bit about
>SGML, there is NO WAY that I would ever write this so as to say "just
>...
  I've been silent about this because I've been overwhelmed and because 
it is an issue I know little about.  However, with the understanding 
that we've done a lot of work in using SGML as an interchange model for 
very complex structured data, one caution about adopting an SGML model:
especially if any kind of minimization is used, it tends to not nest
well: low-level element definitions tend to have a lot of knowledge 
about their environments.
  This is, of course, not a problem if one promises to never try to use 
Nathaniel-mail to transport an SGML document, but that is, of course, 
the very first thing some of us would try to do.  In a way, the need for 
SDIF is symptomatic: with a different SGML nesting model, one might just
be able to apply the thing recursively, with a DTD containing "SGML
document" elements, and not need a separate Standard and set of
definitions.   I don't consider that particularly harmful, incidentally: 
for what SGML is designed for, clean recursion and nesting are not 
necessarily assets, especially in comparison to what they got by not 
having them.
     --john