A common Limitation of information classification systems is the INABILITY to

A.
Limit the number of classifications.

B.
Generate internal labels on diskettes.

C.
Declassify information when appropriate.

D.
Establish information ownership.

Explanation:
I could not find a reference for this. However I do agree that declassifying information is harder to do
the classifying, but use your best judgment based on experience and knowledge.