Everyone I know uses the White = Unexposed/Black = Exposed format. As for empty….. When I load film into them they go into Zip Lock bags, two per bag, where they stay until I take them out for exposure. Like many people, when I make an exposure, I make two, and to add a little insurance I make them from different holders. They go back into the bag until development time.
When I empty them in the darkroom they don’t go back into the bags until they are cleaned and reloaded. So if they are naked on the shelf in the darkroom they are empty.
I only use one film so marking the holder for film type is unnecessary but I do have them numbered on each side so I can track the exposures.
Before I started using the Jobo processor, I developed in trays and it was hard to keep track of which piece of film came from which holder I solved that by filing notches in the inside edge of the flap using Roman Numeral numbering with a straight notch for an I, a vee notch for a V and a half round notch for a X. It worked great but I haven’t needed it with the Jobo because the cylinders are numbered and I know what went into each.
Jerome