Find a symbol by opening Safari (or your choice of alternative iPhone browsers) and searching "squared symbol," or if you happen to be reading this article on your iPhone, here's a free one: ² ...

There can be an X over an image that looks like a sweet, or a tub of water, even a triangle on your piece of laundry and that's not all. An X can appear across a square symbol, on top of an iron ...

We wanted something simple to remember, which is why we went with icons or symbols, and I came up with the triangle-circle-X-square combination immediately afterward. I gave each symbol a meaning ...