How are Patterns Described?

General idea... from Alexander

IF    you find yourself in CONTEXT
      for example EXAMPLES
      with PROBLEM
      entailing FORCES
THEN  for some REASONS
      to construct SOLUTION
      leading to NEW CONTEXT and OTHER PATTERNS
Graphical notations can help, expecially with showing relations among pattern objects/classes. But they are not sufficient.

We need to give several types of information about the problem domain, the forces acting in the sytem, and the resolution to which a pattern is to be applied.

This is not the only format used to describe design patterns but it is a popular one, from the GoF text.