The non-core roles are those roles which are not mandatorily required for the Scrum project and may not be continuously or directly involved in the Scrum process. However, knowing non-core roles is important as they could play a significant part in some Scrum projects. Non-core roles can include the following:

1. Stakeholder(s)
2. Vendors (Customers, Users, Sponsors)
3. Scrum Guidance Body (SGB) – this is an optional role but highly recommended to formalize organizational practices related to Scrum.