You will never get a list that makes everyone happy. I can think of one specific member of this forum that will rip into the citrus comment. I'll comment on a few things myself. It may not sound like it, but I applaud this person for putting together a list and making the effort. It is not easy. And a lot of things on either the "good" or "bad" list have qualifications that could move them to the other list. Some of the things on the restricted list will not cause damage on a one time basis. A chicken will not drop dead the instant they eat a bite of many of these things. It is cumulative damage over time that causes the harm. A lot of times that damage is not fatal. It can make them inefficient or possibly weaker or more succeptable to other things. Some things might be bad for a laying flock that are fine for a meat flock. It is a complicated subject that someone can always pick apart. Even an amateur like me can pick at it.
It is not potato peels that are bad. It is green potato peels that contain the dangerous substance. If you wish you can avoid all potato peels, but it is just the green ones that pose the danger.
Another is apple seeds. Apple seeds, like a lot of other fruit seeds, contain cyanide, a deadly poison. When is the last time you died from eating an apple seed? You don't die, you don't even get sick, because there is not enough cyanide in one apple seed to kill you or a chicken. There are a lot of things on this "good" list that contain something that if you feed it in excess can cause damage, even one of the favorite treats, cabbage. But if fed in moderation, they don't do any damage and with some of these things they would have to eat a tremendous amount over time to cause any damage. I have absolutely no concerns with my chickens eating apples that fall down in the orchard. They will eat the seeds, but they won't eat enough to cause a problem. But when I make apple butter and have a whole lot of seeds, I don't dispose of those seeds where the chickens can get to them.
Uncooked beans contain a substance that can cause damage, but again a little bit won't hurt. I don't worry about them picking through the bean plants that I pull from the garden that may have some uncooked beans still on them. But when I pick through a bunch or dried beans for storage and wind up with a bunch of discards, I don't put them where the chickens can eat a whole lot of them.
I mentioned cabbage. I feed mine a fair amount of cabbage and related stuff and don't worry about it. You would have to feed a whole lot of cabbage to have any problems, pretty much to the point where they did not eat much of anything else. The main key is moderation in any of it.
