Kindly, review the license page for more information about Multiple Authors Partnership.
UPDATE: Could Your Project Integrated Into Another Author’s Projects to be Sold?
If you develop a project could be integrated into another author’s projects like WordPress Plugins, You will need to ask your clients to purchase an Extended License of that project, But because of new Envato rules since January 2013 your clients cannot integrate your projects into their projects to be sold Unless you make an agreement between you.
Envato Castle new option Could Used In-Stock? will help you to transform your clients’ licenses from Extended License into In-Stock License with sending the agreement email to your verified buyers.
A default template for that email is available in the plugin settings, But if you need to make different email for each item, you have a Rich TextEditor for that purpose.
Note: be sure to install and Configure WP Mail SMTP in your website to be sure that the emails will be sent correctly.
Your clients will use this form from Verify User Licenses or Display User Licenses front-end pages to convert their Extended License into In-Stock License.