I put numbers inside my notepad let's say from 1 to 10 and name it. Let's say for example number 1 is craigslist, number 2 is olx etc. and when I see on my Hit tracking page Key Code I look in my notepad and know where it is and am I doing something wrong or not. Of course you can use generalization so you can put same number for all classified ads and next number for traffic exchange and etc.