stack and the sockets API.
4.2BSD was released in 1983.
-Earlier major BSD releases included \fI3BSD\fP (1980), \fI4BSD\fP (1980),
-and \fI4.1BSD\fP (1981).
+Earlier major BSD releases included
+.IR 3BSD
+(1980),
+.I 4BSD
+(1980),
+and
+.I 4.1BSD
+(1981).
.TP
.B 4.3BSD
The successor to 4.2BSD, released in 1986.