This one is from the Jefferson Davis Parish in Louisiana. Named after the President of the Confederacy, the parish has now reportedly adopted a municipal ordinance banning “saggy pants” including showing underwear. (The Jefferson Davis Parish municipal code is only current to December 2013).
Such a ban is most likely unconstitutional – – – especially if it criminalizes the showing of “underwear.” It can also be a masquerade for racially discriminatory policing.
There’s more on the unconstitutionality of criminalizing “saggy pants” in Dressing Constitutionally including cases in which courts have held such laws unconstitutional under the Fourteenth Amendment’s Due Process Clause and the First Amendment. In the same chapter, there is also an extensive discussion of prohibiting the wearing of the Confederate flag.