Alt key codes give you access to hundreds of special ASCII characters, from accent marks to tiny icons. We show you how to use the Alt codes and also Word's Symbol library.

The aviation alphabet is a phonetic alphabet that is commonly used among pilots. The International Civil Aviation Organization, or ICAO, developed a list of codes that coordinates to the letters ...

DNA's instructions are written in a code of four molecular "letters," labeled A, C, T and G. For the first time, researchers have created and inserted two brand-new letters into a living cell.