wtmp utmp - bit confused

[David Collier]

My set-up has a line

    [ ! -f /var/log/wtmp    ] && touch /var/log/wtmp

in S50proftpd

but no equivalent in S40telnetd

And indeed an ftp login does make an entry in wtmp, but a telnet login
does not.

This doesn't seem very consistent so can I ask:

1. is there an "official position" of the use of these files
2. what else in busybox might use them?

TVM

David