Be polite: Assume that your users are trying their best. Don’t use a patronizing or accusing tone. If possible, offer a suggestion about how to correct the error. If the error might be due to a privacy problem, explain why you need the data. If the error might be due to a category problem, explain why you have restricted the categories on offer.1733 ↱
Forms that Work
Designing Web Forms for Usability
Caroline Jarrett, Gerry Gaffney