definition of "first character of each word"

Dear Editors:

Section 7.16.6 (text-transform) of the 1.1 WD specifies the following for
the "capitalize" option: "Puts the first character of each word in
uppercase." This would seem to require no explanation. However, consider the
following example, submitted by an able FOP developer:
http://marc.theaimsgroup.com/?l=fop-dev&m=102736687117494&w=2

<fo:block>
  <fo:wrapper text-transform="capitalize">
    e<fo:wrapper>x</fo:wrapper>tensible</fo:wrapper>
</fo:block>

The submitter of this example and I have both, perhaps through intuition,
thought that the desired result here would be the text "Extensible", i.e.
that text uninterrupted by non-text leaves should be considered as
contiguous. However, while researching tree sibling issues on another
matter, I came across this posting:
http://lists.w3.org/Archives/Public/xsl-editors/2002OctDec/0004
This posting exposes some ugly clarity issues related to 4.2.4, which it is
not my purpose to discuss right now. However, if I apply the principles in
this posting to the above problem, my reasoning becomes this: 1. Because
neither pre-order nor post-order traversal is specified, I may not use
either, but am confined to looking only at siblings. 2. Under these
circumstances, "E", "X", and "T" are each the beginning of a word. 3. The
transformed text will be "EXTensible".

Is this logic correct? Or is some clarification required to 7.16.6? Or,
perhaps I have overlooked something.

FWIW, I did check the CSS2.1 CR, and found nothing to clarify the matter
there. I tried the following html/css code in IE 6.0:

<p>
  <nobr style="text-transform: capitalize;">
    e<nobr>x</nobr>tensible</nobr>
</p>

<p>
  <em style="text-transform: capitalize;">
    e<em>x</em>tensible</em>
</p>

Both cases render "Extensible" (the second in italics of course). If this
rendering is correct, then I suppose that 4.2.4 and 7.16.6 need to be
clarified, as well as other sections that rely on the reasoning used in the
posting cited above, such as 7.15.12. I would ordinarily submit a proposed
change to clarify the intent, but, as you can see, I am still not clear on
the intent. Any guidance you can provide will be appreciated.

Victor Mote