The new rules mean that members must tell press officers that they have had contact with a member of the media even if the meeting is in a social setting and not planned.
Any member who fails to follow these rules may be subject to disciplinary action.
The rules say: “All contact with the media or communication in public by members of the Armed Forces and MoD civilians on defence topics must be authorised in advance.”
The published document also states that members of the wider media are included.
"These rules still apply if individuals encounter: journalists or other members of the news media in a social setting (whether work-related or not); third party individuals with known links to the media, such as commentators, academics, representatives of industry, think-tanks or lobby groups, or former serving personnel with a media profile.”
Members of the armed forces are also restricted in their social media usage and must apply for authorisation to comment on "non-contentious" issues that regard the defence forces.