What does WP mean in UNCLASSIFIED

WP stands for Weather Proof.

Items become Weather Proof by using special materials and parts that are designed to handle the extremes in temperature, humidity and pressure which could occur in various weather conditions. 

The benefit of having a product be Weather Proof is that it can last much longer than regular products since it can withstand varied weather conditions. Additionally, it provides additional protection from certain elements like rain, snow, etc. 

Making a product Weather Proof typically requires specialized materials, which can make the production process more expensive and time consuming than usual. Furthermore, these kinds of products tend to be heavier and less versatile than regular ones due to their protective components. 

Apart from consumer products, other applications of WP technology include roofing sheets, surveillance cameras and emergency power systems used during emergencies when extreme weather conditions may deform or damage conventional equipment.