Names in Unicode Programs

In a Unicode system, all source codes are stored in Unicode. Only the following characters are permitted in names:

1. The letters "A" to "Z"
2. The digits "0" to "9"
3. Underscores "_"

For compatibility reasons, the characters "%", "$", "?", "-", "#" and "*" are also possible, but should only be used in exceptional cases (for example, in existing program generation). A forward slash "/" is also possible for namespace prefixes.

Note

So that programs can be transported from a Unicode system into a non-Unicode system with no conversion loss, no characters should be used in a Unicode system that cannot also be displayed in a non-Unicode system, including characters in comments and literals.