The website for the National Society of Newspaper Columnists, referred to by TimesWarp analyst Barbara Erickson, seems to have been taken down. However, another site has the text of its code of conduct for columnists:
As a newspaper columnist, I will strive to inform, educate and entertain my readers. I will work hard to provoke them to think — whether they agree or disagree with my efforts to depict truth as I see it.
I will offer my opinions and the reasons I hold them as clearly and as fairly as I can. I will never take advantage of my position to achieve unwarranted personal gain not available to others or use my column to settle personal scores. I will disclose potential conflicts to readers whenever possible. [emphasis added]
I will never make up a quote, a source or a story when depicting true events. But I will reserve the right to engage in parody and satire.
I will work hard to earn and keep the trust my readers and editors place in me. I will never plagiarize. Whenever possible, when I make a mistake, I will correct it.
I will listen to my critics and, in person, treat them with dignity and respect because they pay me the high honor of reading me, even if they disagree. Similarly, I will treat with personal courtesy those whom I may criticize in writing before and after writing about them.
I will always remember that my job is a privilege and honor because being a columnist represents the basic American rights of free speech and open discussion.
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Regarding Brooks' conflict see http://alisonweir.org/journal/2014/10/8/my-email-to-new-york-times-public-editor-about-david-brooks.html