Does Japan have one as well?
Japan's press appears to work differently than ours. According to an article in the German newspaper Die Tageszeitung, in Japan there are 800 press clubs which reside directly in offices in the ministries, industrial companies and so on, about which they report. Only the largest newspapers and tv stations have access to these press clubs. The accredited journalists work full time for these press clubs. As a result, these journalists can publish only those facts that they receive from those institutions inside which they reside, otherwise they will lose membership in those press clubs. In the last 30 years the "insider media" have not uncovered one single scandal.
If you search for something like "press club system Japan", you will find a multitude of results, and among them you will note that the Japanese press clubs indeed publish so-called "guidelines", e.g. the Kisha Club Guidelines. What the actual implications of these guidelines are in the face of the above describe practice, you will have to consider carefully.
Hope this gives you some ideas for your research.