This International Standard specifies an interchange format to facilitate the moving of files or parts of files containing data records between computer systems. The interchange format is not intended as a record format for the indigenous files of any specific system but may be used for this purpose. The standard defines a generalized structure which can be used to transmit, between systems, files or records containing a wide variety of data types and data structures. It specifies the means for the description of the contents of data records but does not specify their application semantics although these semantics can be included as a part of the transmission. The interchange format may also be used to transport individual records, individual data fields or individual subfields with their description. This International Standard specifies: media-independent file and data record descriptions for information interchange; the description of data elements, vectors, arrays and hierarchies containing character strings, bit strings and numeric forms; a data descriptive file composed of a data descriptive record and companion data records that enable interchange to occur wifh minimal specific external description; the data descriptive record that describes %he characteristics of each data field within the companion data records; three levels of complexity of file and record structure; FTAM unstructured and structured document types