Silver Threads and Iron Chains

While the differentiation is obvious at times, in other cases it just takes experience - experience that you've said you don't want to have.

And no, implied understanding doesn't mean guesswork. It comes from learning the culture. That doesn't mean that everyone who participates has a correct understanding of everything that's implied, but it's not that difficult to learn the basics. It's simply not necessary to spell out all the exceptions, except for beginners.