In order to prevent spam and other nuisance, contributors to this site must be approved. Fortunately this is pretty easy. Just send Charles a request. You can reach him at an email address you may already have or at email@example.com , although he can be a little slow to respond to the later. He will either know and approve you, or at worst possibly ask you a question or two by email. Then you will receive a password with which you may log in and contribute.