In modern EQ, the placeholders for rares have unique names different from the general zone populace. Generally 3-5 PHs each. This same bug was last seen at the launch of ToV, in which it was fixed in the January patch.
I think they do have unique (i.e. different from normal trash mobs) names. It's just that every single mob in the area where a named is supposed to spawn is spawning as a placeholder, instead of having placeholders mixed in with the trash mobs.
Or the higher con mobs in that area are supposed to be the PH? But I have seen them spawn from the lower cons also....
