There are two types of PK symbols - one is given for NP (National points) and second is given for LP (Ladder Points).
Symbols given for NP - they are given for TOP 200 players on each side. They have border around them.
Symbols given for LP - they are given for TOP 200 players on each side. They do not have border around them. Ladder points are reseted every month.
There are 6 types of symbol based on position in rank. If you have any of those symbols, you can get small amount of money as reward (on daily basis) - you can take reward in behind Luferson/El Morad Castle.
In below table you can see, what position in rank you need to get some specific symbol and also reward which you can get.