Google is now using DNS CNAME records to verify that you are the owner of your site or domain for Webmaster Tools. Google says new verification option will to those users who aren’t able to create DNS TXT records for their domains.
For using DNS CNAME record verification in Webmaster Tools, add your domain to your account and select your domain registrar option and then you will either see the instructions to set a CNAME record or see a link to the option CNAME record. Then click ‘verify’.
“When you click Verify, Google will check for the CNAME record and if everything works you will be added as a verified owner of the domain,” says Google software engineer Pooja Wagh. “Using this method automatically verifies you as the owner of all websites on this domain. For example, when you verify your ownership of example.com, you are automatically verified as an owner of www.example.com as well as subdomains such as blog.example.com.”
She also informed that webmaster can continue to use other verification methods like the HTML file, the meta tag or Google Analytics tag.