Depth-first search. Depth-first search (DFS) is an algorithm for traversing or searching tree or graph data structures. One starts at the root (selecting some arbitrary node as the root in the case of a graph) and explores as far as possible along each branch before backtracking.
Derivative classification is: the incorporating, paraphrasing, restating, or generating in new form information that is already classified and the marking of the new material consistent with the classification of the source material, or the marking of the information in accordance with an authorized classification guide.
Duplication or reproduction of existing classified information is not derivative classification. Persons who apply classification markings derived from source material or as directed by a classification guide need not possess original classification authority. (b) Responsibility.