We see considerable confusion, where people using that feature insist that they don't have to add a "CNAME". In other cases, people using the Blogger / GoDaddy DNS Configuration wizard will think that the second "CNAME" is being added for them.
Right now, everybody has to add their own domain ownership verification token - aka the second "CNAME". We're hoping that the (currently offline) "Buy a domain" wizard will automatically add the domain ownership verification - just as it adds the other DNS addresses - but we'll see that, when we see it. The Blogger / GoDaddy wizard should, likewise, take care of this, on your behalf - but right now, it doesn't. The bottom line? If you go to the Publishing wizard, and see
Error 12or a variant, after typing the domain URL into "Advanced settings", better get busy.
What not all blog owners realise is that the new "CNAME" must be just that. Blogger is not being arbitrary, or pedantic, in requiring precision.
- It must be a "CNAME". A "TXT" will not work.
- The "Name" value must be specified precisely as supplied (Plus or minus the trailing period!).
- The "Destination" value must be specified precisely as supplied (Plus or minus the trailing period!).
If the registrar for your domain does not allow the addition of this "CNAME", you will need to setup a third party DNS host for your domain. You do have to add this second "CNAME" - even if this may conflict with older Blogger Help instructions.