Nonexhaustive Lists

"Et cetera", or rather, "etc." is essentially a symbol which means "this is a nonexhaustive list." The list of examples should provide enough information to explain what you are talking about, but you are explicitly saying that there are more things than the ones you mentioned.

In the grand scheme of things, people rarely make exhaustive lists. For one thing, we usually can't say with confidence that we listed everything, and for another thing, it's usually unnecessary and annoying to do so. (Imagine if you asked somebody what music they liked and then they went off on a three-day rant like Bubba talking about shrimp in Forrest Gump.)

That said, you do not always need to use "etc." at the end of a non-exhaustive list. It has gained a negative reputation around certain circles. If every list you make ends in "etc.", some people will think that you use it whenever you run out of ideas, or when you can't think of a third example.

More importantly, if you say that a list "includes" the examples you then list, it is understood that it's nonexhaustive. Similarly, if you preface a list with "for example", you get the same effect. In fact, the only time people will think that a list is exhaustive is if you specifically use wording that sounds like you are listing every example.

I do like lists. I find them to be great ways to explain a concept in a short amount of space. Because I can see the connections between objects and I can understand what an author is explaining quickly by reading a short list of examples. Because I like them so much, and specifically because I use them so much, I always need to be sure that I don't overuse them. One of the nice things about "etc." is that it sticks out easily enough and it's a simple way to count how many lists I've used.