Forum/board Format Questions

Can anyone help me out, I was wondering:

Why are some post writers names in blue, and others in black ?
What does the red lock on the envelopes represent ?
Is there anywhere on this site that will explain this sort of stuff?

Thanks, I'm just a beginner :-)
~AngelBaby
By "post writers", I mean the "Started By" column...
The names in Blue are those who have registered. The ones in Black have not registered. The envelopes are explained if you scroll down to the very bottom of the page. In addition to that, if it has a black dot, that means that you have posted on that thread. And, if it has a picture of a red lock, that means somebody has been a bad girl or boy and the powers that be locked the thread from further posting.
Thank you very much!!