I'm guessing that I have not yet understood how to use abbreviations/synonyms correctly, but why does it make a difference if I call the synonyms "abbreviations" or "tests"? That is why do the following two files produce different results on my PC (Windows 7, context version  2011.02.09 16:42)? In the first case I get the abbreviation in capitals, in the second case, no capitals. What would I have to do to get small capitals? I tried "style=smallcaps", but that only gave me capitals all of the same height, and no small capitals.

fileone.tex:
%----------------------
\definesynonyms[abbreviation][abbreviations][\infull]
\setupsynonyms[abbreviation][criterium=all,style=cap]

\abbreviation{ABR}{An Abbreviation}

\starttext
Here goes \infull{ABR}.
\placelistofabbreviations
\stoptext
%----------------------

filetwo.tex:
\definesynonyms[test][tests][\infull]
\setupsynonyms[test][criterium=all,style=cap]

\test{ABR}{An Abbreviation}

\starttext
Here goes \infull{ABR}.
\placelistoftests
\stoptext

Best regards, 
Julian