In order to support multiple conventions and clubs a unique URL had to be used that represents the platform supporting the conventions and clubs.  I already had this domain so I used this domain for the platform.  

When you are signing up for an account and receive an error message that the “username is taken”.  This means that you already have an account on the RCS platform and will just have to perform a Password Recovery to create a new password so that you can login.  Since this platform supports multiple conventions and clubs, your account information was entered through one of the other conventions or clubs.

From the main page of your convention there should be a button that says "Registration / Events / Merchandise".  You will need to be logged in to the platform to register for a convention.  Click on this button and the events will be displayed on the product page.  Add the event you want to attend to the shopping cart.   After you have entered the events and products to the shopping cart you can proceed to checkout to complete the registration.