Not to be served at critical diplomatic dinners. (Deb Lindsey/For The Washington Post)

Critical Loop Information Bulletin for all heads of state, foreign ministers and their chefs:

An excellent meal of fine food and wine has often been the key to successful diplomatic negotiations. So if you’re hosting Secretary of State John Kerry, here are some critical pointers.

In arranging a dinner with the former senator last year, one host asked whether Kerry had meal preferences.

One aide e-mailed: “Anything is good, as long as there is no celery involved.” Celery?

Shades of President George H.W. Bush’s war on broccoli back in 1990, when he banned the offending vegetable from the White House and Air Force One, famously declaring: “I do not like broccoli. And I haven’t liked it since I was a little kid, and my mother made me eat it. I’m president of the United States, and I’m not going to eat any more broccoli.”

The edict, banning the offending vegetable from the White House and Air Force One, outraged broccoli farmers and the nutrition-minded.

But simply eschewing celery — while sure to upset the farmers — isn’t very much to go on when you’re putting on a full dinner.

So a second aide, apparently speaking with deep knowledge, refined the menu suggestions:

“He particularly enjoys scallops . . . You’ll also do well with lamb chops, sheperd’s pie, simple salad, clam chowder, chocolate desserts, ice cream. Apple juice, water, Zinfandel wine, Sauv Blanc. He doesn’t drink coffee and the celery restriction is accurate.”

Sounds all very New England, maybe a bit old-fashioned. (But best not go overboard into a New England boiled dinner or creamed chipped beef for brunch.)

Good to know Kerry drinks water, but unclear whether sparkling or still, so offer both, just not tap.

Remember, a well-fed secretary of state could be the margin of difference in tense negotiations.