I am told that in Nevada, an obvious unobstructed Flap Holster can be considered 'concealed' Carry, even though it is worn openly and obviously.
'Can' be...meaning, the Authorities have the option of making it a crime, if the wearer is not a CCW holder...if they want to bust someone's chops about it.
Open Carry, where enough of the Handgun 'handle
' is visible sticking ut of an open-top Holster, and not covered by a Flap Holster's Flap top, is simply Open Carry, legal for anyone possessibng intact Civil Rights, but liable to vagueries of location/context.