The elements of the PBI (product backlog item)

• Independent - No dependencies
• Negotiable -
• Valuable -
• Estimable - explicate clear and understood
• Small - enough to be fit inside a sprint
• Testable - can I see when it happened

The Characteristics of the product backlog Item format

• Description
• Order
• Value
• Estimate - explicate clear and understood

These items are often defined using Agile Communication Frameworks