Any open source project may choose to purchase a commercial user subscription to enable additional privacy features. Proprietary projects require a commercial use subscription.

Project's with a commercial-use subscription may have private-by-default bugs, and you may also request the setup of private code hosting. As the maintainer of a project with a commercial-use subscription, you may create private teams with private mailing lists and package archives. Any project may have a commercial-use subscription to enable commercial-features.

You can purchase a commercial subscription at the Canonical store Commercial subscriptions cost US$250/year/project + applicable V.A.T. If you select 'Other/Proprietary' as the project license, the project overview page also shows the directions to purchase a commercial use subscription

Read more about a commercial subscription to Launchpad