binary file
Binary files with a defined record structure are considered as special external extents. Binary files (or flat files) are supposed to have a fixed data format for all attributes, i.e. a fixed position and length. Binary files may contain ASCII or binary fields.
Binary file extents can be weak-typed, i.e. they may consist of instances with different types, as long as the type is coded in the common base structure.
Generalisations: external file
Specialisations: flat file, hierarchical file