Frantisek Holop noticed (on the OpenBSD lists) that gzip's -k is undocumented in NetBSD. Patch below.
--- usr.bin/gzip/gzip.1.orig +++ usr.bin/gzip/gzip.1 @@ -128,6 +128,10 @@ with the option, allowing non-compressed data to pass through unchanged. .It Fl h , -help This option prints a usage summary and exits. +.It Fl k , -keep +This option prevents +.Nm +from deleting input files after (de)compression. .It Fl l , -list This option displays information about the file's compressed and uncompressed size, ratio, uncompressed name.