I recently read a thread on Notary 123 regarding the infamous "less but not more" rule. The supposed rule goes something like this: If a signer's I.D. says John Paul Smith, you can notarize their signature as John Paul Smith, John P. Smith, or John Smith. But if a signer's I.D. says John Smith, you can only notarize their signature as John Smith, not John Paul Smith or John P. Smith. The zeal with which supposedly experienced notaries stand by this idea is quite impressive. But when asked to provide where in their state statute or notary handbook this rule exists, the soft shoe dance begins. No one can provide any law or statute that supports this rule. They do, however, insist that it's true because the National Notary Association SAYS it's true. Say what? The NNA is NOT some sort of notary governing body. They don't make the rules and they don't enforce the rules. They are a FOR PROFIT organization. They are a marketing machine. They speak in generalities with little regard to the rules of each individual state statute. And they are wrong. A lot. Just because they're the loudest voice in the crowd doesn't mean they're right. And just because you've always done it that way or that's how you were taught doesn't make it right either.
Your state handbook and state statutes are the only sources that ultimately matter. Know your handbook and take what you hear elsewhere (including here) with a healthy dose of caution. Most states allow you to identify someone based on "satisfactory evidence". If you are satisfied that they are who they say they are based on the acceptable I.D. provided, you're free to notarize away.