[2] The ln command by default creates hard links, and when called with the command line parameter ln -s creates symbolic links.

[4] The ln command can however be used to create symbolic links to non-existent files.

[5] The version of ln bundled in GNU coreutils was written by Mike Parker and David MacKenzie.

[6] The command is available as a separate package for Microsoft Windows as part of the UnxUtils collection of native Win32 ports of common GNU Unix-like utilities.

Specifically, The specification also specifies the command line options that must be supported: If neither target file nor target directory are specified, links will be created in the current working directory.