(a) Standard. The standard to be used by the Board in making any advisory determination relating to the loyalty of a United States citizen who is an employee of, or is being considered for employment in, a public international organization of which the United States is a member, shall be whether or not on all the evidence there is a reasonable doubt as to the loyalty of the person involved to the Government of the United States.

(b) Activities and associations. Among the activities and associations of the employee or person being considered for employment which may be considered in connection with a determination of disloyalty may be one or more of the following:

(1) Sabotage, espionage, or attempts or preparations therefor, or knowingly associating with spies or saboteurs.

(2) Treason or sedition or advocacy thereof.

(3) Advocacy of revolution or force or violence to alter the constitutional form of government of the United States.

(4) Intentional, unauthorized disclosure to any person, under circumstances which may indicate disloyalty to the United States, of United States documents or United States information of a confidential or non-public character obtained by the person making the disclosure as a result of his previous employment by the Government of the United States or otherwise.

(5) Performing or attempting to perform his duties, or otherwise acting, while an employee of the United States Government during a previous period, so as to serve the interests of another government in preference to the interests of the United States.

(6) Membership in, or affiliation or sympathetic association with, any foreign or domestic organization, association, movement, or group or combination of persons, designated by the Attorney General as totalitarian, fascist, communist, or subversive, or as having adopted a policy of advocating or approving the commission of acts of force or violence to deny other persons their rights under the Constitution of the United States, or as seeking to alter the form of government of the United States by unconstitutional means.