The
.Ar command
argument is mandatory unless
-.Fl C
+.Fl C ,
+.Fl L ,
or
.Fl s
is specified.
.Pp
+The user will be required to authenticate by entering their password,
+unless configured otherwise.
+.Pp
+By default, a new environment is created.
+The variables
+.Ev HOME ,
+.Ev LOGNAME ,
+.Ev PATH ,
+.Ev SHELL ,
+and
+.Ev USER
+and the
+.Xr umask 2
+are set to values appropriate for the target user.
+.Ev DOAS_USER
+is set to the name of the user executing
+.Nm .
+The variables
+.Ev DISPLAY
+and
+.Ev TERM
+are inherited from the current environment.
+This behavior may be modified by the config file.
+The working directory is not changed.
+.Pp
The options are as follows:
.Bl -tag -width tenletters
.It Fl C Ar config