1)You yell d-up when you are on the block and only when you are the 1st to see the cops. You say d-up just to let everyone around you kno they are there.2) You can also call the cops D-Up too. Depending the situation could mean, "RUN"
1)"AYo D-UP the law coming up the one-way!"
2)"Thats D-UP over there in that parked taurus, with the tints"