For what it's worth, my understanding of the underlying logic behind this
seemingly nonensical state of affairs is as follows.

1. <s> was originally provided for one purpose only: the end-to-end
segmentation of linguistic corpora. This means it should be used with the
following constraints:
  -- every word in the textt must be contained by one <s> only
  -- <s> elements may not be nested inside other <s> elements

2. <seg> was provided for those, not a few, who considered the above
   restrictions unreasonable. In particular,
  -- <seg>s may appear at arbitrary places within a text
  -- <seg>s may be nested within other <seg>s

Where things get complicated, is when you start trying to fit <s> and
<seg> into the TEI class structure. Clearly both <s> and <seg> are
phrase-level, in the sense that they can occur multiple times within a
single chunk-level item (such as a <p> or an <ab>): this defines where
they are permitted in the DTD.

There is however a clear inconsistency in their contents: <s> can contain
only other phrase-level elements, whereas <seg> can contain either
phrase-level or inter-level elements such as <q> and <bibl>. Why that
should be, I am not sure, but presumably it is because of the greater
generality of application envisaged for <seg>: you might well want to
tag as a single segment something containing a <q>. You may retort that
the same is true of <s>, and maybe you're right, but that's not the way
<s> was originally envisaged (see above) -- the assumption was that if
you found something new inside an <s> (such as a <q> or a <bibl>) that,
ipso facto, was enough to warrant a new <s>.

As with all other such questions, this is one that can be reconsidered by
the Tech Council, now that we have one.

Lou

p.s. yes I know that the P4X model for <s> now includes <s> even though it
says in the text it's not allowed. This is a consequence of xmlification,
which doesn't permit exclusion exceptions. In P5, this restriction,
if still required, will be achieved by a schema rule


On Tue, 19 Mar 2002, Guy Aston wrote:

> <p>
> <s>"As it is", Guy said, "it seems confusing". </s>
> <s>And confusion, as the bible tells us (TEI guidelines, Chicago & Oxford)
> is to be avoided.</s>
> </p>
>
> The dtd states:
>
> 1.
> <s> cannot contain <q> or <bibl>
> <s> can contain <seg>
>
> 2.
> <seg> can contain <q> and <bibl> (and, interestingly,  <s>)
>
> In other words,  I can tag a stretch inside an <s> as <q> or <bibl>
> providing I put it inside a <seg>.
>
> <p>
> <s><seg type="sbit_q"><q>"As it is"</q></seg>, Guy said, <seg
> type="sbit_q"><q>"it seems confusing"</q></seg>. </s>
> <s>And confusion, as the bible tells us <seg type="sbit_bibl">(<bibl>TEI
> guidelines, Chicago & Oxford</bibl>)</seg> is to be avoided.</s>
> </p>
>
> So why shouldn't I? Or is this an error in the dtd?
>
> Guy
>