Algol 68 values may be either plain values or stowed values. Plain values, such as integers, real numbers, strings and the like, are atomic and so not composed by other values. Stowed values, i.e. multiples and structure values, on the other hand, are composite and consist on collections of other values. The values collected in a multiple are all of the same mode and are known as the elements of the multiple value. The values collected in a structure value may be of different modes and are known as the fields of the struct value. Each field has a name, known as its field selector, which is unique within the structure value, and also a value.