19 Filenames 19.2 Pathnames 19.2.2 Interpreting Pathname Component Values 220.127.116.11 Restrictions on Examining Pathname Components
18.104.22.168.6 Restrictions on Examining a Pathname Version Component
The version can be any symbol or any integer.
The symbol :newest refers to the largest version number
that already exists in the file system
when reading, overwriting, appending, superseding, or directory listing
an existing file.
The symbol :newest refers to the smallest version number
greater than any existing version number when creating a new file.
The symbols nil, :unspecific, and :wild have special meanings and
restrictions; see Section 22.214.171.124 Special Pathname Component Values and Section 126.96.36.199 Restrictions on Constructing Pathnames.
Other symbols and integers
have implementation-defined meaning.