Do you write "See ID", back of credit cards?

I have few active credit cards but I only wrote " See ID" on the signature panel instead of writing my signature, because I believed that will help prevent fraud. But I was reading on an article about credit cards, says that according to Master Card and Visa Card when a merchant sees "See ID" on the back of the card instead of the signature that card should not be processed. But, I have been using and swiping my card in any store but nobody says anything except some of them are checking my identification which is for me is okay.

What that signature really means? The card companies remind customers that the signature panel isn't just for verifying the signature. It's also used to validate the contract you have with the credit card company. By signing, you confirm that you agree to their terms. And even though you may choose not to sign the card but use it anyway, you still are bound to the terms and agreements set forth by the issuer.