Type of grenade used extensively during the Vietnam War. Upon detination, white phosphorous is spread over a wide area. While often used offensively, it's most prolific use was with tank, aircraft and helicopter crews. Upon the eventuality that they had to abandon their vehicle, they would detonate a WP grenade on equipment they did not want to fall into enemy hands.
White phosphorous is a particularly horrific weapon due to the fact that phosphorous reacts violently with water, thus any attempts at extinguishing the fire would result in it getting worse.
Troops were uneasy about using WP as it is very unpredictable and it has a high spread radius.
The radio designation for White Phosphorous is Willie Pete.
Better bring a few Willie Petes for this fire mission Bill, we don't wan't Charlie getting his hands on these XM16's...