If :wild
is the value of a pathname component,
that component is considered to be a wildcard, which matches anything.
A conforming program must be prepared to encounter a value of :wild
as the value of any pathname component,
or as an element of a list that is the value of the directory component.
When constructing a pathname,
a conforming program may use :wild as the value of any or all of
the directory, name, type,
or version component, but must not use :wild as the value of the host,
or device component.
If :wild is used as the value of the directory component in the construction
of a pathname, the effect is equivalent to specifying the list
(:absolute :wild-inferiors),
or the same as (:absolute :wild) in a file system that does not support
:wild-inferiors.