Hey. My suggestion would be for BYOND to create a new world variable that could do basically the same function as invisibility and see_invisibility, but instead of working with a number, it would work with a text string. For example, you could set a ghost's invisibility_string variable to "Ghost", and then change every witch's see_invisibility_string variable (Which could be a list to add more than one value) to "Ghost"; that way, only witches could see Ghosts and no one else would be able to.