[closure-devel] Use of (make-pathname ... :type :unspecific)

In src/parse/html-parser.lisp, there's this form:

(make-pathname :directory '(:relative "resources") :type :unspecific)

19.2.2.2.3 says this:

Whether a value of :unspecific is permitted for any component on any given file system accessible to the implementation is implementation-defined. A conforming program must never unconditionally use a :unspecific as the value of a pathname component because such a value is not guaranteed to be permissible in all implementations.

CLISP signals an error on the form.

What's the :type :unspecific for? It seems to work on CLISP (and all other implementations I tried) without it; is it a precaution against a *default-pathname-defaults* that apparently has a value for :type?

Zach