title: Documentation on passing parameters to event url
body: <p>I am working on developing an integration between EventBrite and a CRM platform.  In order to sync data back to the CRM platform I would like to pass a query string variable of the customer id to the EventBrite event url and have that data passed back to me when I query the API.  Is this possible?  If so is there documentation on what query string variables are available?</p>