A pocket sandwich is a sandwich which is made using a single piece of folded or hollowed bread, such as a pita, which is made from dough cooked with fillings inside.
The US Army has developed shelf-stable pocket sandwiches as combat feeding rations (the First Strike Ration) for its troops on-the-go. The sandwiches are engineered to prevent microbial growth through the use of specialized water treatment, acidic content (naturally, through ingredient selection; or by the addition of food-grade acids), special multi-layer foil packaging, and oxygen-absorbing packets.[2]