About PVP-Skull System

[pelichjohn]

What do these skulls mean and how do they affect players?
So far I haven't been able to determine anything.

[iromax]

when a player opens combat with another player, he is marked with a skull icon, that icon changes color according to the number of deaths he caused, these skulls represent the amount of penalties that he receives at home another player kills him , penalties with loss of XP and more.