A validation code—also known as a CVV, CV2, or CVV2 code—is a series of three or four numbers located on the front or back of a credit card.

Most top-ranking websites fail HTML validation. Google explains why perfect code isn’t required, and what matters instead.

Here's how to integrate the ASP.NET CustomValidator control with client-side code to create a page that uses Ajax and server-side code to validate data at the browser.

Take advantage of FluentValidation to validate your model classes when working with minimal APIs in ASP.NET Core 6.