Re: i guess there's some of both

Hmm, the VB I use doesn't even have namespaces...

Anyway, the main idea with namespaces is that you can import the namespace, then you can treat the words in the namespace as any other.

So the idea is, you'd stick USING QB64 or something near the beginning of your code, and then you can use things like BYTE, ROUND, SNDPLAY, just like any other keyword.
The advantages are:
Having such a statement near the beginning of your code automatically identifies it to the reader as QBASIC incompatible, rather than having to scan for underscored keywords.
QB64 keywords can be underscore free, so they look prettier, more readable, and more like part of the language.
If you use enough new features, the method will pay for itself on keystrokes anyway.

The main disadvantage is, there are some words that can no longer be used as variables/functions. The main problem with this though, is only when you're taking a program written in QBASIC and expecting it to compile without changes. And that will still be possible. If you're writing specially for QB64, you can make sure to avoid the new words as you're writing the program.