McDonald’s Universal Icons for 109 Countries [pdf]
The older I get, the more I'm convinced that icons are not a terribly good way to convey information. Some things and concepts, sure. Others, not so much.  Especially in technology and science.Navigation can make good use of icons. Left, right, up, down, start, stop, these kinds of things can be learned and used widely.  Somethings like text manipulation icons, cursors, insertions, selections, can be used effectively, but can be surprisingly hard to explain or even describe. Icons for operations can be really tough.  Right now as I look at my computer I can see a library of arcane and archaic imagery.  Telephones, disks, pen nibs, VCR controls (navigation, sort of), little boxes with arrows, little boxes overlapping, deadbolt locks, paper airplanes, file folders, fluffy clouds, paperclips, and of course little hamburgers.These can certainly be useful clues, but they also can be very confusing.  I've seen paint brushes used to indicate a paint brush in a paint program, but I've also seen the exact same icon used to indicate a screen refresh.  Now I'm at as much a loss as anyone to come up with a good substitute, although I will note that I can't imagine any _good_ circumstances when a user needs to be in charge of refreshing the screen.These days I'm using a lot of 3D software, and the user interfaces are a crust of complicated and indecipherable icons. And that's just the top layer of the UI. Almost all of them rely on a text/label system and hot keys for doing much of the work. Discoverability is essentially zero and the only way to get good is to learn the words and the alphabet.  Pros end up _hiding_ most of the UI.Sometimes a word is worth a thousand pictures.The only one of the icons in the link that make much sense is the one with kcal on it.  Unless I dealt, in detail, with these everyday, I'd never remember what the rest stood for.  Something like this may make a lot of sense for the people that produce the labels, but I'm unconvinced it does anything good for those who need to _read_ the labels. Word labels in the intended reader's language is almost certainly the best way to go for actual use.