Isn't supplying :unspecific as the value of :type always to be avoided?
The CLHS says:
"Portable programs should not supply :unspecific for any component." [documentation for function MAKE-PATHNAME]
and in section 19.2.2.2.3 :UNSPECIFIC as a component value
"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."
So instead of supplying this for a couple of cases and then trying to avoid it for others, shouldn't we be avoiding it altogether?
I confess that I don't fully understand this issue, since it seems like the CLHS makes it clear that NIL is /not/ fully equivalent to :unspecific (since the latter is not "overwritten" in a merge), and yet tells us not to use the latter....
If anyone can clarify this, it would be great....
Best, r