Two chars - fixed amount. One control, one command. Just cleaner, simple and functional. It's something you type, and it is hidden, you want it to be short and clear.

«How is that different», more literally: it is markup, like in htMl, but it is a special markup for that other special purpose of direct rich text tagging in word processors, not for hypertext (HTml). I called it differently, but if you so fancy, it is DRTTIWPML.