(b) (1) Reveal the identity of a confidential human source, a human intelligence source, a relationship with an intelligence or security service of a foreign government or international organization, or a nonhuman intelligence source; or impair the effectiveness of an intelligence method currently in use, available for use, or under development
(b) (3) Reveal information that would impair U.S. cryptologic systems or activities
(b) (6) Reveal information, including foreign government information, that would cause serious harm to relations between the United States and a foreign government, or to ongoing diplomatic activities of the United States
(b) (7) Reveal information that would impair the current ability of United States Government officials to protect the President, Vice President, and other protectees for whom protection services, in the interest of the national security, are authorized
Redaction codes:
https://www.archives.gov/declassification/iscap/redaction-codes.html
(b) (1) Reveal the identity of a confidential human source, a human intelligence source, a relationship with an intelligence or security service of a foreign government or international organization, or a nonhuman intelligence source; or impair the effectiveness of an intelligence method currently in use, available for use, or under development
(b) (3) Reveal information that would impair U.S. cryptologic systems or activities
(b) (6) Reveal information, including foreign government information, that would cause serious harm to relations between the United States and a foreign government, or to ongoing diplomatic activities of the United States
Missed one :P
(b) (7) Reveal information that would impair the current ability of United States Government officials to protect the President, Vice President, and other protectees for whom protection services, in the interest of the national security, are authorized