I agree with Steve on this one (he gave his reason in another reply). To state it a little differently: the fact that the feature can still be used means that someone might suggest that you use it. Knowing what it does and why you shouldn't use it is certainly beneficial, as it will help prevent the situation where you unwittingly use it. Deprecated doesn't mean that it will ever be fully removed. So it never really hurts to know as much as possible about the environment in which we are working. People often use inferior / problematic features because they haven't been removed and some people don't know any better, such as not using TEXT / NTEXT / IMAGE datatypes, and a lot of other things. Remember, "knowing is half the battle!" 😉

Take care, Solomon..