is a variable defined in `
Its value is
((cms . ange-ftp-cms-make-compressed-filename)
(vms . ange-ftp-vms-make-compressed-filename))
Alist of host-type-specific functions to process file names for compression.
Each element has the form (TYPE . FUNC).
FUNC should take one argument, a file name, and return a list
of the form (COMPRESSING NEWNAME).
COMPRESSING should be t if the specified file should be compressed,
and nil if it should be uncompressed (that is, if it is a compressed file).
NEWNAME should be the name to give the new compressed or uncompressed file.