Error Message Text - Best Practices

Question

We are changing some of the text for our old, badly written error messages. What are some resources for best practices on writing good error messages (specifically for Wind

Answer 1

1. Avoid identical error messages coming from different places; parametrize with file:line if possible, or use other context that lets you, the developer, uniquely identify where the error occurred.
2. Design the mechanism to allow easy localization, especially if it is a commercial product.
3. If the error messages are user-visible, make them complete, meaningful sentences that don't assume intimate knowledge of the code; remember, you're always too close to the problem -- the user is not. If possible, give the user guidance on how to proceed, who to contact, etc.
4. Every error should have a message if possible; if not, then try and make sure that all error-unwind paths eventually reach an error message that sheds light on what happened.
   
   I'm sure there will be other good answers here...