zzffoorrccee [[ _f_i_l_e ...... ]]The command zforce examines each file, and adds the suffix .gz to it if it had been compressed with gzip. If adding .gz would make the file's name longer than 14 characters, zforce truncates the file's original name to make room for the suffix.
You should use zforce to prompt name compressed files, to ensure that gzip does not compress a file twice. You can also zforce can be used to examine files whose names were truncated during file transfer, and properly stamp those that were compressed.