Raw data can be organized
in several ways. External files can contain data that is arranged
in columns or fixed fields. It is possible to specify a beginning
and ending column for each field.
However, the following
file contains nonstandard data, because one of the variable’s
values includes a special character, the dollar sign ($).
The following external
file contains no special characters, but its data is free-format,
meaning that it is not arranged in columns. Notice that the values
for a particular field do not begin and end in the same column.