A basic understanding of keyboards and how they work around the world can help avoid problems in application development.
National group
The national group is used for languages which use a script other than Latin. This is called Group 2 in ISO9995. This group is normally selected by pressing shift-alt, but this varies by platform, and can be customized. To type a theta (θ) using the Greek keyboard you would first switch to the Greek layer using shift-alt, and then press the key U key (or the θ key in Greek). The national group is normally engraved on the right side of the key.
