Separating links in issue screen

[Jon]

Hi, 

I was wondering how i can customize the reference number that is show on the main issue table. Right now we are linking contracts and shipments and they all have the same reference number, e.g.  ES-1. However when we are viewing this we see multiple links but cannot determine if its linked to the contract or shipment because they all have the same prefix "ES". Is there anyways to add another column so i could have contract links and shipment links? Or, is there a way to change the way links are reported, change the ES on one of them so we could deduce that what type of link it should be. 

thanks, 

jon