See ID

I used to be asked to show my ID every time I was paying by my credit card, and yes you are right, I did not sign the back of my credit card (That is how it works in Canada, they are taking it to the next level for entering a PIN number though). Today I was asked to show my ID again, but I noticed no one has asked me to show my ID for last two months. Surprisingly, I could successfully stop ID checks without signing the back of my credit card. You are probably confused, but it is not that complicated. Instead of signing the back, I simply wrote “See ID” on the signature area. It was supposed to make cashiers to ask more about my ID, but to my surprise it worked the other way !

Does anyone has a rational explanation for the fake trust created by writing such a sentence? The first question I asked myself was if the sentence created some sort of trust, or it is just because people do not like to do what they are told to do. What makes people more trustful when you directly tell them what you expect them to do!? I will start to do some research to find a proper answer to my question.