+connections. If the unit is already in use a dynamically allocated number will
+be used.
+.TP
+.B ifname \fIstring
+Set the ppp interface name for outbound connections. If the interface name is
+already in use, or if the name cannot be used for any other reason, pppd will
+terminate.
+.TP
+.B unset \fIname
+Remove a variable from the environment variable for scripts that are
+invoked by pppd. When specified by a privileged source, the variable
+\fIname\fR cannot be set by options contained in an unprivileged
+source. See also the \fIset\fR option and the environment described
+in \fISCRIPTS\fR.