best-practices seems like an easier to recognize term than software-practices. I've seen the former plenty of times but the later only here.

Ok, I added that as a short description for now, while the community figures out what this tag should be. We can edit, rename, or remove later, as needed.

If it is on-topic, then there is no reason to create a tag for this - it becomes a meta tag. It is in my opinion better to spend the effort into drafting help pages for how to ask these kind of questions.

As for the cast to void question, it isn't even subjective. There's industry consensus that doing so when a return value isn't used is mandatory, save for a number of old standard library functions that aren't used in that way out of tradition.

For some reason never got around to answering this: "As for the cast to void question, it isn't even subjective."

It is subjective as long as it isn't a completely technical question - as the standard allows it, the choice of whether or not to do it falls under best practices.