Which are the Scrum artifacts and commitments?

Scrum defines the following artifacts:

• The Product Backlog, which is an ordered, dynamic, and incomplete list of items that serves as the sole source for the work of the Developers;
• The Sprint Backlog, which is a plan that contains the work that the Developers of the product believe they will carry out during the Sprint in order to implement one or more Increments and which defines the value to be created;
• The Increment, which is the done result of the implementation of one or more Sprint Backlog items by the Developers during the Sprint and is usable by the product’s customers and users, potentially representing value to them.

Their corresponding commitments are also defined:

• The Product Goal, which expresses the central goal or motivation for the Scrum Team’s work in developing the product and to be satisfied through implementation of the items in the Product Backlog. The Product Goal is the commitment of the Product Backlog;
• The Sprint Goal, which expresses a clearly defined goal for a Sprint to be carried out or satisfied through the implementation of items from its corresponding Sprint Backlog. The Sprint Goal is the commitment of the Sprint Backlog;
• The Definition of Done, which is a formal understanding shared between the Developers and the Product Owner of what is necessary for them to consider any item in a Sprint Backlog or any Increment to be done.

As an option to be added to Scrum, I suggest one more:

• The Definition of Ready, which is a formal understanding shared between the Product Owner and the Developers of the product regarding the state in which an item in the Product Backlog should be in order to be considered ready to enter the Sprint Backlog, and therefore to be implemented. I understand that the Definition of Ready can be seen as another commitment of the Product Backlog, since its items should meet it in order to be able to enter a Sprint and be implemented.