What additional information must be provided if 'danger close' is announced during a call for fire?

When 'danger close' is announced during a call for fire, it indicates that the fire will be delivered at a range that places friendly forces at risk of taking fire. In such critical situations, it is essential to have the Ground Commander’s initials to confirm their approval for the engagement. This additional verification from the ground command ensures that all parties understand the risks involved and that the decision to engage is fully supported at the command level.

Having the Ground Commander’s initials also helps ensure the accuracy of the communication. The approving authority acknowledges the potential danger posed to their own forces and emphasizes the urgency and necessity of conducting the fire mission under those specific conditions. Proper adherence to protocol in these situations significantly enhances coordination and safety in combat operations.

The other choices, while they might be relevant in different contexts, do not carry the same critical weight in terms of quickly validating and confirming the authorization necessary under 'danger close' circumstances.