From what I've seen, every company has a different idea of what _best practices_ are.
And that's fine. "Best practices" don't necessarily need to be universal in scope. Read the Knowledge Management literature and you'll see plenty of discussion of the idea of scoping "best practices" to in terms of "site best practice", "company best practice", "industry best practice" and so on.
There's also a lot of discussion about using different language other than "best practice" exactly to acknowledge that "best practices" aren't always BEST practices, if you get what I mean. Calling them something like "recommended practices" or "proven practices" or similar lingo gives a way to denote things that are recommended at least locally, without having to claim that they are either universal in scope, or absolutely "best" in any sense.
From what I've seen, every company has a different idea of what _best practices_ are. Generally comes down to what some influential developer likes.