Challenge of producing guidelines to address different needs. Some
users:
  - Need audio and synthesized speech;
 
  - Need images, video, and graphics;
 
  - Require time-independent control (e.g., those using serial access or
    with physical disabilities);
 
  - Require space-independent control (e.g., can't use the mouse to navigate
    in two dimensions);
 
  - May have more than one disability.
 
Note: Plain text help content is not the
best solution.