Byte and is also combined with metric prefixes for multiples, for example ko and Mo. The usage of the term "octad(e)" for eight bits is no longer common. Despite standardization efforts, ambiguity still exists in the meanings of the SI (or metric) prefixes used with the unit byte, especially concerning the prefixes "kilo" (k or K), "mega" (M), and "giga" (G). Computer memory has a binary architecture in which multiples are expressed in powers of 2. In some fields of the software and computer hardware industries a binary prefix is used for bytes and bits, while producers of computer storage devices
Zero-byte file be zero bytes (a common convention terminates text files with a one- or two-byte newline, however). Conversely, zero-byte files must use some disk space to be indexed by a filesystem (though none for content, in most cases). In some cases, zero-byte files may be used to convey information like file metadata (for example, its filename may contain an instruction to a user viewing a directory listing such as documents-have-been-moved-to-partition-D, etc.); or to put in a directory to ensure that it is nonempty, since some tools such as backup and revision control software may ignore the empty directories. There are many