Hi Andrew

Thank you very much. Just a few concluding notes:

1.
----
<xsl:template match="CELL">
<td><xsl:apply-templates select="SB"/></td>
</xsl:template>
----

I know my example didn't show it, but in Real Life there are an awful lot of
things in CELLs, and every so often amongst them there is a run of SB
elements which I want to collapse in this way. So the above is too simple,
unfortunately. (There also may be two runs of SB with some other intervening
element, as well.)

<xsl:template match="CELL">
<td><xsl:apply-templates/></td>
</xsl:template>

...for the very reason that youv'e found - you want to apply-templates
to all elements, and just do nothing <SB> elements that arent the
first in a sequence of <SB> elements as they will be processed by a
moded template.

2.
----
<xsl:template match="SB[preceding-sibling::*[1][self::SB]]" priority="2"/>
----

This I have added - it should kick in for any SB selected (without a mode)
whether or not 'select="SB"' was specified on the apply-templates node,
right?

3.
When I experimented by interspersing random elements amongst the SB runs, I
found that they were each appearing twice. I see now, I think, that Dr Kay's
templates presumed that the "higher-order" template was only selecting the
first <B> child, hence the need to include
----
<xsl:apply-templates select="following-sibling::*[not(self::b)][1]"/>
----
(or [not(self::SB)] in my case) after the closing <B> in the main template.
As my "higher-order" template (I don't know what the canonical term is,
sorry) is simply doing a general <apply-templates /> then non-SB children
are pulled in anyway. So I dropped that line as well.

Correct, you don't need that line if the template matching the parent
element has called apply-templates.  You would need that line if the
parent called apply-templates on the first element only, and then each
template would call apply-templates on the appropriate
following-sibling.  Its just two different ways of walking the tree.

On the samples I have tried since making these changes, it seems now to be
doing what I want.

cheers
andrew