The process of this tool works like this. Let's say you have some news for a friend, but you want to fool them with a weird URL. So you insert the URL http://news.google.com/ and you want to modify it using the identifier. To use the custom identifier, you simply declare that you want to use your custom identifier and fill the custom value out. If you don't want to use the custom identifier, you are more than welcome to use the random identifier that is assigned as a random alphanumeric value.
URL e.g. http://www.prestigecode.com/?url=identifier -> http://news.google.com/