-may be specified which is usually
-.Pa /var/log/wtmp
-(or
-.Pa /var/log/wtmp.[0-6]
-depending on site policy as
-.Pa wtmp
-can grow quite large and daily versions may or may not
-be kept around after compression by
-.Xr ac 8 ) .
-The
-.Pa wtmp
-file contains a record of every login, logout,
-crash, shutdown and date change
-since
-.Pa wtmp
-was last truncated or
-created.
-.Pp
-If
-.Pa /var/log/wtmp
-is being used as the file, the user name may be empty
-or one of the special characters '|', '}' and '~'.
-Logouts produce
-an output line without any user name.
-For more information on the
-special characters, see
-.Xr utmp 5 .