Originates from a the Swedish beer named Dansk Fadol which is cheep but still looked at as a fine beer. Drinking this in the park/streets would not bee looked at as a lower class activity but as casual outside drinking.
A Fadoler would normally be of a young age (18-30) or he would be referred to as a bum/alcoholic depending on his looks.
Trashy clothes and ungroomed beard at age 45 drinking Fadol in the park = bum
Youngster full of life drinking Fadol in the park with his Fadoler friends(not moaning about the flaws of society) = Fadoler
Jim and Dave drinking Dansk Fadol in the park:
Jim: (downing his 10th fadol) This is a very nice park for Fadoling! Where should we head next?
Dave: Indeed this is some great Fadoling! We should head over to the benches by the town square and pick up some babes