is this possible to add reference material to a specific order form, so that reference material will always be available in the projects for this specific client without adding it each time?
the way to to do it is to use cloud service like Dropbox, Box or Google Drive ... create a custom field and add the link to material as default. So that these materials are always added in the project when creating an order.
1. Create custom field for project in Settings >> General Settings >> Custom field
2. In the New Order Form, choose the Project settings tab
3. Add the default value for the newly created custom field