Type declaration statements explicitly define the data type of
specified symbolic names. There are two forms of type declaration
statements: numeric type declarations and character type
declarations.
Type declaration statements can initialize data in the same way as
the DATA statement: by having values bounded by slashes and listed
immediately after the symbolic name of the entity.
Type declaration statements must precede all executable statements.
The data type of a symbolic name can be declared only once.
Once a symbolic name has been used in a context that implicitly assumes a data type, its assumed type cannot be changed by a type declaration statement.