The category of the selling plan. For the `OTHER` category,
you must fill out our [request form](https://docs.google.com/forms/d/e/1FAIpQLSeU18Xmw0Q61V8wdH-dfGafFqIBfRchQKUO8WAF3yJTvgyyZQ/viewform),
where we'll review your request for a new purchase option.