# Registration form support Top-up items Use case\ \- For a conference event, the organizer could create a main ticket, known as the Pass-ticket, and set up different Add-on items as separate breakout session tickets. Only attendees who have purchased the Pass-ticket can then purchase Add-on items. And you can further set the Add-on item restriction, only those * For User flow --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://eventx-hq.gitbook.io/knowledge-base/registration-and-ticketing/registration-form/registration-form-support-top-up-items.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.