What information must be provided if the shell fuse combination is not given?

The correct answer specifies the requirement to provide a target description including size and type when the shell fuse combination is not given. This information is crucial because the type of munitions and fuses used can greatly affect the effectiveness of the fire support on the target. Knowing the size and type of the target allows the forward observer to recommend the appropriate ammunition and fuse combination that would best suit the target characteristics, ensuring that the desired effects can be achieved effectively.

For example, if the target is a hard structure, specific munitions may be necessary to achieve penetration, whereas a soft target may require different ammunition types. Thus, this information is vital in ensuring that the fire support is tailored correctly to maximize combat effectiveness and minimize collateral damage.

Other potential answers, while important in their own right, do not address the immediate need for guidance on ammunition and fuse selection as directly as a target description does.