Hashing is the file-access method used by D3 to find items in a file.
The characters composing the item-ID are combined to produce an internal number that is then divided by the modulo of the file to determine which group the item resides in. The group is then linearly searched until the item is found.
The hashing is done by default in a case insensitive way, that is, a and A yield the same hash value. This can be changed on a file-by-file basis by changing the file-defining item from a type D to a type DS.