Communicating error messages accessibly

This is a detailed recommendation for making application erros accessible ...

"I propose the following requirements for error message presentation in web applications:

Error messages should be accessible for as many users as possible regardless of culture, age and impairment.

• It should be easy to understand that an error has occurred.
• It should be clear what the user has to do to correct the error.
• It should be clear for the user where the error was found in the form.
• It should be possible to be notified about errors before submitting the form, especially if it is a complex form that takes time to process on the server.

All errors should be displayed at the same time. Noone wants to re-submit the form to find a new error."   continued ...   (Via Standards-schmandards)