* False: Product Owners do not have to specify complete acceptance criteria for a Product Backlog item before the Developers can select the item in Sprint Planning.
* Acceptance criteria are a set of conditions that a Product Backlog item must satisfy to be considered
"Done" and acceptable for delivery.
* Acceptance criteria are not mandatory in Scrum, but they can help the Product Owner and the Developers to clarify the expectations and requirements of a Product Backlog item.
* Acceptance criteria can be added or refined by the Product Owner at any time, but they should be clear and testable before the Sprint starts.
* The Developers can select a Product Backlog item in Sprint Planning based on their understanding of its value, scope, and complexity, as well as their capacity and skills. They can also collaborate with the Product Owner to define or refine the acceptance criteria during Sprint Planning. References: Scrum Guide, Section 3.4 (The Product Backlog), Section 5.1 (Sprint Planning), and Section 6.4 (The Increment)