Many file systems permit more than one filename to designate a particular file.
Even where multiple names are possible, most file systems have a convention for generating a canonical filename in such situations. Such a canonical filename (or the pathname representing such a filename) is called a truename.
The truename of a file may differ from other filenames for the file because of symbolic links, version numbers, logical device translations in the file system, logical pathname translations within Common Lisp, or other artifacts of the file system.
The truename for a file is often, but not necessarily, unique for each file. For instance, a Unix file with multiple hard links could have several truenames.
220.127.116.11 Examples of Truenames