I was researching something in the NLV muni code, and thought I would visit one of our "most talked about" ordinances, but it was this one that caught my eye.
9.32.050 - Person with concealed weapon not to loiter.
It is unlawful for any person, while carrying concealed upon his person any dangerous or deadly weapon, to loaf or loiter upon any public street, sidewalk or alley, or to wander about from place to place with no lawful business thereby to perform, or to hide, lurk, or loiter upon or about the premises of another. It is unlawful for any person who has concealed upon his person any dangerous or deadly weapon to loiter about any place where intoxicating liquors are sold or any other place of public resort.
(Prior code § 7.22.050)
Since it says nothing about OC, it stands to reason that you "must" in order to be legal, uncover in public if you don't want to "State your business"