What does classification reason 1.4(B) and 1.4(D) mean?

Question

The weekly standard had a sensationally titled piece that was picked up and linked to by the Drudge report that claimed it was proof that Hillary Clinton knew she sent classified info over her personal email, which would be a violation of federal regulations regarding the handling of classified information by government officials and employees.

The article includes this image:

However it appears the content of the email was officially classified on 30 July 2015, quite a ways after the original claim that Hillary never sent classified information. However it is possible that the reason for the official classification was that the content was something that should always have been considered classified.

So the question is, What does reason 1.4(B) and 1.4(D) in the confidential reason memo mean?

Answer 1

Most classified info in the US is National Security Information, and classification procedures are defined in Executive Order 13526. Section 1.4 is the categories of classifiable info, and (b) and (d) are:

(b) foreign government information;

(d) foreign relations or foreign activities of the United States, including confidential sources;

Nothing is classified under EO13526 from the date it's created; it needs an affirmative action to be classified (nuclear secrets are, but that's under the Atomic Energy Act). However, foreign government information (1.4(b)) is presumed to be classifiable (i.e. presumed damaging to national security if disclosed). Also, if you incorporate previously classified info into a new document, you are supposed to classify the new document as well.