The @command{gzip} file format is specified in P. Deutsch, GZIP file
format specification version 4.3,
-@uref{http://www.ietf.org/rfc/rfc1952.txt, Internet @abbr{RFC} 1952} (May
+@uref{https://www.ietf.org/rfc/rfc1952.txt, Internet @abbr{RFC} 1952} (May
1996). The @command{zip} deflation format is specified in P. Deutsch,
DEFLATE Compressed Data Format Specification version 1.3,
-@uref{http://www.ietf.org/rfc/rfc1951.txt, Internet @abbr{RFC} 1951} (May
+@uref{https://www.ietf.org/rfc/rfc1951.txt, Internet @abbr{RFC} 1951} (May
1996).
@node Sample