This Standard ECMA-41 specifies file structures for data interchange on magnetic tape cassettes.
To provide for the range of sophistication in equipment and applications three systems are specified.
The BASIC System employs only hardware-defined separators to structure the files.
The COMPACT System employs special data blocks with information content (labels), which are capable of being recorded using only numeric equipment.
The EXTENDED System employs the magnetic tape labeling system described in Standard ECMA-13 together with new labels, to define a more comprehensive labeling system. This Standard is not limited to the 3,81 mm magnetic tape cassette described in Standard ECMA-34, but could also be applied to higher capacity cassettes or cartridges.