So, negative effects. The reward for annoying other people, or just trying to raise a reputation.
Lets start when you annoyed people.
-Ball and chain, remove with a locksmith, or prevent by greasing yourself with fatty salves.
-Injuries, ask a nice healer who can heal you, or drink a potion of healing wounds according to the level of your wound.
-Hexes (though you gotta admit, you got that one cause that one guy in your clan needs to hex a thousand people in a day cause he wants that red medal asap), you can heal it with the help of a BoV member (arch-apotrope), or a scroll of exorcism.
-If for you a BoV bless is a negative effect (on your opponent), whip out your Mamaluk's croiser and remove that stuff!
-Lost Soul (classic arena stuff), remove it with a thurrible (DoC rep) or a bugle of lost soul.
From the top of my head, I feel like these are the ones I know for level 10 and below.
Here's some that you tried to raise a reputation.
-Burn, ask a BoV dude with at least green medal, if he stocks these scrolls, to remove it using a healing burn scroll.
-Mark of Death (though you have to admit you wanted that one for naked hunting and was not picking cuckoos). Ask a Bov member with blue medal, he can remove it with a Scroll of Blooming.
Other instance of negative effects.
-Splinters! (the famous one), ask a nice person to remove it with a first aid kit.
There are probably more negative effects for level 11+ that I'm not really aware yet (there's a destructor, no idea what it does, I'll get to it someday)