what are the current rules reguarding thieves and permagrey?

[UncleSham]

this applies to player thieves in the thieves guild and personal defense .
now i remember a while back anyone who was in the thieves guild was freely attackable even if they appeared blue . (known as permagrey)
then i believe something got changed to they were attackable if they had stolen from you . or was it they had to fail and thus turn grey ? no im prety sure failing made them truly grey .  but this is why i ask .
does a top end thief ever actually fail ? (i doubt its often if they do at all)
i know some of them want you to flag on them so they can kill you .  i usually just leave , but ive considered trying to fight back . i just dont want to get guardwhacked defending myself.

anyone know the current rules ?

[ii & Sabin]

In a guard zone if you attack them when they are blue - you get guard wacked. If they are grey - no problem.

If you kill them outside a guard zone when they are blue they can not give you a murder count.

Permagrey is no more!

@120 stealing i think it is like 90% to succeed but i am not sure on this.

[Podolak]

I haven't played a thief in ages but you can attack them no matter what if they've just stolen from you right?