The following guidelines for writing good error message incorporate those from Jakob Nielsen's Alertbox ("Error message guidelines").
- in the same language as the originating page;
- human-readable language, instead of obscure codes or abbreviations such as "an error of type 2 has occurred.";
- polite phrasing that doesn't blame users or imply that they are doing something wrong;
- precise descriptions of the exact problems; and
- constructive advice on how to fix the problem.
Note that all feedback/error messages should be in the language of the page that the user is reading.