I can’t stand the use of ALL CAPS in text.
A light touch on the caps-lock key is not just a good strategy for emphasizing the right things, but also just generally for making text easier to read. Because we see words as shapes, big rectangular blocks of all caps take us much longer to process.
Of course, if you’re trying to make something hard to read, then all caps is the perfect choice. Companies that set safety warnings in all caps may, intentionally or not, veil important information from consumers.
Here’s a version of the Surgeon General’s Warning that appears in Edward Tufte’s masterpiece Visual Explanations. The warning appears on a cigarette billboard and has been artfully concocted in ALL CAPS, underlined, and surrounded by a dark black border.
So why do we use all caps instead of bold or italic or even highlighted? Because back when lawyers used typewriters, the only simple way to emphasize anything was to use ALL CAPS.