How to avoid a line break in a <phrase>

I want to use the role attribute on <phrase> to do something like

<para>Some content <phrase role="keeptogether">qwerty asdf 
zxcvbn</phrase> some more content</para>

to avoid any line-breaks being generated in the <phrase> content when 
I produce a PDF file.  (A sort in in-line equivalent of 
<literallayout>?)

Is there a way to do this?

Ron
-- 
Ron Catterall, Phd, DSc			        	email: 

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