The url validation function used when adding websites information to contacts and organizations does not allow hyphens '-' in the domain name.

The error "Please correct the following errors in the form fields below: Enter a valid web location beginning with 'http://' or 'https://'. EXAMPLE: http://www.mysite.org/" is displayed if you try to enter a URL for the website of a contact or organization that includes a hyphen, such as in http://www.atoz-sado.com

If I remove the hyphen, the contact or organization is saved without a problem.