In the not-too-distant past, to save progress in some of your games, you'd be given a password of some kind. Which was usually fine until you get something like this one from Super Castlevania IV.

Now, what're you supposed to do with that? Draw a little 4x4 grid and draw symbols in each of the squares? Write out the words "heart, space, space, holy water", etc.?

Well, you could do those things, but I prefer to substitute numbers for the symbols. Like so:

Then the code becomes:

Which is much easier to write down, much easier to type, and much harder to screw up. It's a win-win...win.