'''Extended file attributes''' are [[file system]] features that enable users to associate [[computer file]]sfiles with [[metadata]] not interpreted by the filesystem, whereas regular attributes have a purpose strictly defined by the filesystem (such as [[file system permissions|permissions]] or records of creation and modification times). Unlike [[fork (file system)|forks]], which can usually be as large as the maximum file size, extended attributes are usually limited in size to a value significantly smaller than the maximum file size. Typical uses include storing the author of a document, the [[character encoding]] of a plain-text document, or a [[cyclic redundancy check|checksum]], [[cryptographic hash]] or [[digital certificate]], and [[discretionary access control]] information.
In [[Unix-like]] systems, extended attributes are usually abbreviated as '''xattr'''.<ref>{{man|7|xattr|Linux}}</ref>
