Muy Complicado!
1.9. "Modifications" means the Source Code and Executable form of any of the following:
A. Any file that results from an addition to, deletion from or modification of the contents of a file containing Original Software or previous Modifications;
B. Any new file that contains any part of the Original Software or previous Modification; or
C. Any new file that is contributed or otherwise made available under the terms of this License.
OK.
There is a file containing Original Software or previous Modifications.
If you add someting to the contents of the file, you have created Modifications.
If you delete someting from the contents of the file, you have created Modifications.
If you make modification of the contents of the file, you have created Modifications.
If you created a new file that contains any part of the Original Software or previous Modification, it is Modifications.
If you created a new file that is contributed under the terms of CDDL, it is Modifications.
If you created a new file that is made available under the terms of CDDL, it is Modifications.
Better?
:)