syslog showing user using root

[John Jimenez]

What is the difference between the "-" sign and "+". To me it looks like the programming consultant has logged in with root? I asked him and he says that he has not logged in with root. But isn't my syslog saying otherwise?
Both of these are from the syslog. The first one is the consultant login name and the next one is mine.

Jun 13 13:21:14 HOST su: - t8b consultant-root
Jun 13 13:24:30 HOST su: + tJd myself-root

[Mel Burslan · Accepted solution]

it means that consultant account has attempted and failed the password authentication when he tried to su to root account, whereas you, myself account were successful when you su'ed to root.

This is what those two lines mean.

[Uday_S_Ankolekar]

- indicates failed logins attempt.

-USA..

[John Jimenez]

Thanks for the info....

[Cem Tugrul]

John,
- shows fail attempts to your system
+ shows succes attempts
Good Luck