This link suggests that /var/empty is a part of most Linux systems too, albeit not defined in the FHS.
The Arch Linux
filesystem package also includes /var/empty so it seems to be "supported".
heir(7) in my Arch box notes:
Code:
/var/tmp
Like /tmp, this directory holds temporary files stored for an unspecified
duration.
Perhaps this would be suitable?
EDIT: ha! Necrobump! Sorry...