type ShortWord = ShortCard;
ShortWord is an unsigned integer type which is not larger than Word. On some platforms it is 16 bits wide and thus has a range of 0 .. 65535. It is the same as ShortCard.
ShortWord in GNU Pascal is compatible to short unsigned int in GNU C.
There are lots of other integer types in GPC, see Integer Types.
ShortWord is a GNU Pascal extension.
ShortWord in GNU Pascal essentially corresponds to Word in Borland Pascal and Delphi where it is a 16-bit unsigned integer type.
program ShortWordDemo; var a: ShortWord; begin a := 42; WriteLn (a) end.