A more thorough explanation:

Prophylactic cost refers to the expenses incurred by a party to prepare their property to prevent potential future harm. These costs are not related to any existing property damage and are usually not recoverable under insurance contracts.

For example, a homeowner may install hurricane shutters on their windows to protect their property from potential damage during a storm. The cost of installing these shutters is a prophylactic cost.

Another example is a business investing in cybersecurity measures to prevent potential cyber attacks. The cost of implementing these measures is a prophylactic cost.

Overall, prophylactic costs are expenses incurred to prevent future harm and are not related to any existing damage.