trust settings, what is this.
DefaultTrust list are moderated by theymos. It is an account [1] . But users can make custom trust list by going trust list [2] . If he like to trust the users who are trusted by the user he adds to his trust list, he can change the trust depth to 1. If he want to trust users who were trusted by the users in trust depth 1, he can change the trust depth to 2 and so on, currently, it can be up-to 4 levels. I hope you understand.

[1]
https://bitcointalk.org/index.php?action=profile;u=122551[2]
https://bitcointalk.org/index.php?action=trust ~~MZ~~
tnx but i didnt understand:) its complicate. and if someone gives negative to my custom trust.do people see it? what appears at my trust now?
If you're asking if you can change your trust rating by changing who is on your trust list, the answer is no. If you change your trust list, that only changes what
you see. What other people see depends on who they have on their trust list, and you can't change that.