Where are FETCH_AFTER_ARGS and FETCH_BEFORE_ARGS defined?

I had this in my graphics/tiff Makefile:

DISTFILES+=     TIFFTechNote2.html
# It is in CVS for Release-v3-6-1, but accidently excluded from distribution.
SITES_TIFFTechNote2.html=       http://remotesensing.org/cgi-bin/cvsweb.cgi/~checkout~/osrs/libtiff/html/TIFFTechNote2.html?rev=1.1&content-type=text/html&sortby=date&only_with_tag=Release-v3-6-1

(Any suggestions how to do that better?)

At first, it didn't work because the "$${site}$${bfile}" didn't have
quotes around it. But then the file was saved with wrong filename.

This could be fixed with -o for curl or our ftp or -O with wget. I was
hoping that this was already done when doing the fetch.

Also, I see PASSIVE_FETCH defines FETCH_BEFORE_ARGS += -p which is not
compatible (not passive mode) for wget nor curl. I think that should be
removed since now -p is the default for our ftp.

What are FETCH_BEFORE_ARGS and FETCH_AFTER_ARGS for?

   Jeremy C. Reed
   http://bsd.reedmedia.net/