Using all caps isn't always shouting
Acronyms, like the one for the Real Academia Española should not be considered shouting.
I think what they mean by no caps, means, when your just typing any old word, and you capitalize it. That is when it seems like your shouting. If you are typing an acronym, then it obviously wouldn't seem like you are shouting since it's proper to capitalize it, if the acronym was a regular word however, it'd probably be nice if made it known to people that it was an acronym not a word.