I would like to output acronyms with the first letter of a word in upper case when they are printed to the list of acronyms. However, it certain cases I would like to print the written out form in lower case (english language) when I add them to a paragraph using the \ac{} or \acf{} commands. A third case would be to use the mixed letter variant somewhere in the document.
Examples:
% 1) In the list of acronyms.
Spatial Reference System (SRS)
...
% 2) In a paragraph.
... the spatial reference system (SRS) is important because ...
...
% 3) Somewhere else in the document.
... it may happen that you still want to use the
mixed variant when writing about the Spatial Reference System (SRS) ....
Question:
- How would you configure acronyms to distiguish between those three cases?

\expandafter\show\csname if@in@acrolist\endcsname? – JJD Sep 10 '12 at 10:33\ACFmacro. – egreg Sep 14 '12 at 17:35