A Word about Language
The reader will have noticed variations in the way terms for what is ostensibly the same thing vary from context to context. The structure names for those that are sub-types of other relationships are a good example of this. Indeed the variations in the names of entity classes themselves also show this.
That is an indication of how this model is a living thing. On the one hand, names of things are extremely important. But on the other hand, recognizing subtle differences in names is equally important.
At a particular level of abstraction, there is an appropriate language to use. At another level, the language may well be different. This is to be expected. Indeed, the names of entity classes in this book are by no means ...