.I gzip
file format is specified in P. Deutsch, \s-1GZIP\s0 file format
specification version 4.3,
-.BR <http://www.ietf.org/rfc/rfc1952.txt> ,
+.BR <https://www.ietf.org/rfc/rfc1952.txt> ,
Internet RFC 1952 (May 1996).
The
.I zip
deflation format is specified in P. Deutsch, \s-1DEFLATE\s0 Compressed
Data Format Specification version 1.3,
-.BR <http://www.ietf.org/rfc/rfc1951.txt> ,
+.BR <https://www.ietf.org/rfc/rfc1951.txt> ,
Internet RFC 1951 (May 1996).
.SH "DIAGNOSTICS"
Exit status is normally 0;
compresses better than
.IR gzip .
.SH "COPYRIGHT NOTICE"
-Copyright \(co 1998-1999, 2001-2002, 2012, 2015-2017 Free Software Foundation,
+Copyright \(co 1998-1999, 2001-2002, 2012, 2015-2018 Free Software Foundation,
Inc.
.br
Copyright \(co 1992, 1993 Jean-loup Gailly