I know you probably weren't expecting to see a bibliography here, but I'm trained as an academic, so it's second nature to me.
Signature, Finger, & Customized Headers FAQ. Edited by Nancy McGough
NOTE: Each finger RFC was obsoleted by the suceeding RFC.
Harrenstein, Ken. RFC 0742, "NAME/FINGER Protocol", 30 Dec 1977.
Zimmerman, D. RFC 1194, "The Finger User Information Protocol", 21 Nov 1990.
Zimmerman, D. RFC 1196, "The Finger User Information Protocol", 26 Dec 1990.
Zimmerman, D. RFC 1288, "The Finger User Information Protocol", 19 Dec 1991.
You should, of course, read your local system's man page for
finger(1).