J. Peng wrote:
> At what cases should we return a DECLINED or a OK from a handler?
> I saw the handler of PerlTransHandler returns a
> Apache2::Const:ECLINED but dont know why.


see the introduction to part III here:

http://www.modperlcookbook.org/chapters.html

in general, trans handlers return DECLINED because they don't typically
do sufficient mapping of a uri to a resource on disk - they usually
alter the uri then let the default apache trans handler do the mapping.

--Geoff