...
- Perceivable
- Operable
- Understandable
- Robust
Principle #1: Perceivable
http://www.w3.org/TR/WCAG20/#perceivable
Principle #2:
...
Operable
http://www.w3.org/TR/WCAG20/#operable
Principle #3: Understandable
http://www.w3.org/TR/WCAG20/#understandable