People often ask about the origins of the cap Mel wore during his nine years on the series. The white cap is, indeed, a Naval hat worn by sailors to this day. They were simply known as "white hats," and were often washed or soaked in salt water to help keep them white and bleached. Navy regulations dictated that the hat only be worn in a certain way - straight in the front and back, with a slight bend of the rims on the side. Excessive bending was forbidden. Mel, however, broke all Navy rules and rolled up his hat on all sides, which effectively gave him the characteristic look of a Navy cook.
Nowadays, however, Navy rules are more lenient and the white hat can be worn in more informal ways. Honor Guards, for example, are seen wearing the hats rolled on all sides.
Authentic white hats can only be found and distributed in the Navy. They are sturdy and very durable. Imitation hats can be purchased from clothing department stores, though they are thinner and made from vastly inferior material. The most common complaints about the imitation hats is that they do not fit correctly and do not hold their shape.
Vic Tayback, the actor who played Mel, got the idea for rolling up the hat from his own experiences in the Navy. He and several Naval buddies repeatedly rolled up their hats, much to the dismay of Naval officers. During their shore leaves, they were sometimes picked up by shore patrolmen and ordered back to the ship to have their hats "refitted." In some cases, they even had their hats confiscated. Vic no doubt took pride in bringing his own Navy experiences with him to the ALICE set. The white hat was distinctive and personalized his role as Mel, and allowed him to finally wear the hat in a way he always desired.