name of line break processing instruction

Hi,

I feel stupid for even asking, but a lot of archive searching still
hasn't given me the answer:

What is the (or a) standard name for the DocBook line break processing
instruction? I've seen <?lb?> and some others. Is there support for
the PI already in the stylesheets? If not, what do I need to add to my
customization layer to enable support in fo, html, and xhtml. My line
breaks will probably occur in table entry cells.

Thank you,

-- 
http://chris.chiasson.name/