What kind of formatting can you use in comments?
See the formatting options.

In my profile, what is showdead?
It lets you see stories that have been killed.

In my profile, what is noprocrast?
If you enable noprocrast, you'll only be allowed to visit this site for maxvisit minutes at a time, with gaps of minaway minutes in between.

In my profile, what is delay?
It is the number of minutes you can edit your comments before they appear to others.