Which describes an off-specification?

An off-specification is a type of issue that must be formally managed. It is defined as something that should be provided by the project but is currently not, or is forecast not to be. This includes products that fail to meet their quality criteria or specifications. Producing more than the defined quantity of a product is a deviation from its specification (which would include quantity) and is therefore a classic example of an off-specification.

A. An interdependency between products that was previously unidentified: This would be logged as a risk or a general issue, not specifically an off-specification, which relates to a product's requirements.
B. The addition of an improvement to a product description: This is a request for change, which is another type of issue, but it is a proposed modification, not a failure to meet an existing specification.
C. A prototype demonstrating a possible design solution: A prototype is a product created to reduce uncertainty; it is not an issue type.
E. That the right people are involved in appropriate roles: This relates to the 'defined roles and responsibilities' principle, not a product-related issue like an off-specification.

AXELOS. (2023). PRINCE2 7 Managing Successful Projects. PeopleCert. Section 11.2.1, "Issue types," defines an off-specification as "something that should be provided by the project, but currently is not (or is forecast not to be). This might be a missing product or a product not meeting its specification."