Unwanted calls happen all of the time. You can choose to hang up, ignore all together, let the machine get it, or even change your number. Those calls come and go, and you may forget about them as soon as they are over. However, when things get sticky, you may want to do something about what is going on. If you find that someone is harassing you in any way, and you feel you may be in danger, you have to learn something about phone codes to help the police and the phone company figure out what is going on and how to stop it. One of the most important phone codes you have to know is the call trace code. This is generally the code *57 through most phone service providers, but it might be different in your case.