The data for the register is right here. You just can't see it because it is meant to be used in a template 'transclusion'. If you are logged in you can click on the  link to the right to change the data for this register. If you are not logged in, you can click on the view source tab at the top of this page to at least see how data is stored here.
It's probably best if you open the edit link in a separate tab. That way you can use this tab to read the explanation of the syntax above or jump back to the place where you came from and see how your changes look there. (Don't forget that your browser cache or the wiki's rendering cache might need some time or persuasion to catch up with the new content.)