Given that the only references I can find online appear to be copies of the Wikipedia entry, I’m a bit suspicious.

Two entries were added by an anonymous contributor: CAKE and RFML.

https://en.wikipedia.org/w/index.php?title=International_Air...

RFML seems from United Airlines, and seems to mean: easy to digest. No egg, no dairy, probably no meat? Its for people from places where food isn't processed or where they had not eaten much for a longer time, so a change in diet content and quantity may be problematic for the passenger.

If you have a citation for that, you should add it to the article.

A lot of airlines have done refugee flights at one point or another, so I guess they needed a way to tell the ground crew to load whatever special foods were needed.

What 'special foods' would be needed for refugees?

If they're famine refugees, something like Plumpy'nut[1] maybe. If they're religious refugees, something catering to their religious restrictions. MREs if the refugee operation is being assisted by a military or disaster aid organization. And so forth.

[1]: https://en.wikipedia.org/wiki/Plumpy%27nut

Talking of MREs, some airlines do not allow them as carry on luggage, see https://www.tsa.gov/travel/security-screening/whatcanibring/....

MREs contain a heating packet filled with magnesium pellets and a couple other things, which are used to heat the food when water is added. I'd imagine they don't want those in the cabin, given the gas that is emitted during the heating process.

There's also TBML which is for Tech Bro Meals (soylent, mainly)

Sounds like a backronym

It’s a euphemism for Soylent Green.

Bread and water

Big Mac Meal.

humble pie