ANSI Common Lisp 19 Filenames 19.1 Overview of Filenames
19.1.3 Parsing Namestrings Into Pathnames
Parsing is the operation used to convert a namestring into a pathname.
Except in the case of parsing logical pathname namestrings,
this operation is implementation-dependent,
because the format of namestrings is implementation-dependent.
A conforming implementation is free to accommodate other file system
features in its pathname representation and provides a parser that can process
such specifications in namestrings.
Conforming programs must not depend on any such features,
since those features will not be portable.