And you ask, "Lift up your shirt" cause you wonder if a tattoo
Of affiliation can make it a pleasure to put me through
Gang files, but that don't matter because the matter is racial profile

from Kendrick Lamar (Ft. Pharrell Williams) – Good Kid Lyrics on Rap Genius

Meaning

The cops ask Kendrick to lift up his shirt because they assume (and hope) that, as a young black kid, he will have a tattoo expressing his gang affiliation. They are looking forward to putting him in their gang files. But that won’t happen because Kendrick isn’t in a gang, and is actually being racially profiled.

This mirrors the way gang members interrogate Kendrick about his gang affiliation to see if he’s with them or against them. The police are just another gang to him. It shows how hard it is for a kid growing up in Compton when despite the fact that he has never joined a gang and tried to stay neutral, both groups treat him like he is in a gang and use it to attack him. When stuff like that happens it’s no wonder so many kids do take a side.

To help improve the meaning of these lyrics, visit “Good Kid” by Kendrick Lamar (Ft. Pharrell Williams) Lyrics and leave a comment on the lyrics box