I don't like these rules of thumb because they are misapplied and misunderstood. You end up having programmers that think they are following rules but still end up making the mistakes the rule is meant to prevent, and restricting themselves from using something that would help them.
It's why the definition of "global" is so important. If a programmer chooses to narrowly apply it to a specific variable type in their language they may entirely miss the point. For example, they might freely use Windows registry values, DB values, or otherwise to achieve the same thing, thinking it's alright since they don't have a mantra against it, and it isn't violating the "global" variable rule.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.