Recently Microsoft has launched the new version of the Microsoft Enterprise Library 3.1. One of the new things in this version of the enterprise library is validation application block.
The Validation Application Block will include a comprehensive library of common validation rules that apply to primitive data types. For example, we'll include rules like string length, numeric range, date range, regular expressions and so on.
I have found a great blog post the describes validation block here is the link for validation block: