Hi Uwe, Thanks, good to know. But in my case I set the language to English (UK) which does load babel. Also the LyX wiki entry I was talking about refers to cases where babel is loaded, otherwise \renewcommand\abstractname{Executive Summary} works.
p.s why did you change the wiki back to the old description. \AtBeginDocument{% \addto\captions<your language>{% \renewcommand{\abstractname}{In nuce}% }} Doesn't seem to work. Roey