f77 extends list-directed I/O to allow internal I/O. @
During internal, list-directed reads, characters are consumed until the input list is satisfied or the end-of-file is reached. During internal, list-directed writes, records are filled until the output list is satisfied. The length of an internal array element should be at least 20 characters to avoid logical record overflow when writing double-precision values. Internal, list-directed read was implemented to make command line decoding easier. Internal, list-directed output should be avoided.