programlisting: line number start value

Are there any suggestions which attributes (and which values) to 
use for <programlisting>s to tell some special XSL stylesheets
(from the DB2LaTeX project) that:

I know that the attribute 'linenumbering' of <programlisting> with a 
value of "numbered" indicates the XSL stylesheets, that the lines 
should be numbered in some way.

Are there any suggestions which attributes (and which values) to 
use to indicate that line numbering for subsequent <programlisting>s
should continue with the value of the last <programlisting>?

The XML will be processed with some special XSL stylesheets from the 
DB2LaTeX project (not the official DocBook XSL stylesheets), which in
general are capable of handling this (for the curious readers: we use 
'Verbatim' from the 'fancyvrb' package for <programlisting>s. 
'Verbatim' itself has an option 'firstnumber=last' which continues
from the previous 'Verbatim' envirnoment).

Michael
-- 
                              http://www.miwie.org