ANSI Common Lisp 19 Filenames 19.3 Logical Pathnames
19.3.1 Syntax of Logical Pathname NamestringsThe syntax of a logical pathname namestring is as follows. (Note that unlike many notational descriptions in this document, this is a syntactic description of character sequences, not a structural description of objects.)
logical-pathname::= [host host-marker]
directory::= word | wildcard-word | wild-inferiors-word
name::= word | wildcard-word
type::= word | wildcard-word
version::= pos-int | newest-word | wildcard-version
host-marker - a colon.
relative-directory-marker - a semicolon.
directory-marker - a semicolon.
type-marker - a dot.
version-marker - a dot.
wild-inferiors-word - The two character sequence "**" (two asterisks).
newest-word - The six character sequence "newest" or the six character sequence "NEWEST".
wildcard-version - an asterisk.
word - one or more uppercase letters, digits, and hyphens.
pos-int - a positive integer.