"why even show this as an error?" is one of my favorite questions. It's the UI equivalent of "make illegal states unrepresentable". > Use human-readable error

"why even show this as an error?" is one of my favorite questions. It's the UI equivalent of "make illegal states unrepresentable". > Use human-readable error messages, and make sure they are understandable to the users/operators of your software (not just developers). Including a specific error code is fine -- it can disambiguate similar errors, and make it very easy to do a 'find all' in source to go directly to the offending spot -- but that doesn't help your user. Yes. Remember, however, that much software needs to be localized, even if the initial developer didn't think to. Error codes are much better than hard-coded English-language error messages; map them to a message at the last possible moment.