Even for directories, it should still refer to hard links.
Example:
Code:
$ mkdir foo
$ ls -ld foo
drwxr-xr-x 2 me me 4096 Sep 15 15:32 foo
Right now there are two hard links:
The latter is the directory's reference to itself.
Let's create some stuff inside it:
Code:
$ touch foo/bar foo/baz
$ mkdir foo/boo
$ ls -ld foo
drwxr-xr-x 3 me me 4096 Sep 15 15:34 foo
Now there are three hard links for the directory. Why? Because now we have:
The last entry is the parent of boo (which is foo). If we create more subdirectories inside foo, the hard links will increase accordingly.