Here's a photo of another house we gutted. Notice the "X" to the right of the window. After Katrina, FEMA (as well as other governmental organizations) went through the hurricane affected homes and applied this numerical system.

On the top middle section of the "X" is the date when they first inspected the house. The number to the right is how many animals were found inside. The number in the middle bottom identifies how many people were found dead in the house and the number to the left is an internal number for their records.