There is a lot of speculation, questions, and misinformation when it comes to legal meats. Here are the SCD rules to live by.
Grocery store meats are often legal. You do have to read labels, but yes, feedlot beef with no additives, chicken, turkey, lamb, and pork are often legal. Chicken is often not legal, so you must read the labels. Anything injected with natural flavorings or broth is not legal. Anything injected with only salt and water is legal.
Just because it is legal does not mean it is OK for YOU to eat. You will not react well to every meat. If you have an allergy to a particular meat, stay away from it. If you know you have an intolerance to a particular meat, then don't eat it. Intolerances often go away with time spent on the SCD, but it's best to err on the side of caution.
Organic meats are not necessarily better. Feedlot beef and conventionally raised chickens are often fed corn and soy. The real kicker? So are many of the ones labeled "organic" -- which means there is very little difference between them and their feedlot-raised brethren. Some extremely sensitive individuals will not be able to eat any meat that was fed corn or soy. As far as beef goes, look for grass fed, grass FINISHED beef. Some meat that is labeled grass fed has actually been finished with corn -- which is no good if you are sensitive. There is a similar issue with eggs laid by hens fed corn and soy. Often, "pasture raised" animals will not be fed corn and soy -- but you need to check with the supplier to be absolutely sure.
Drain fats well in the beginning. Many people have difficulty digesting fats when they first start the diet. Cutting down on the fat can often alleviate this difficulty. Also, the fat contains the most toxins, so it's a good idea to either choose very lean cuts or drain it if you're eating feedlot beef.
And while we're talking about meat, there are a couple of resources that can help you find clean meats. Whole Foods has a bunch of great regulations in place, and their butchers are ready and willing to answer any questions you might have. There are also many Weston A. Price groups who can help you obtain clean, safe meats near you.
But don't forget that your local grocery store may have enough options for you. My local Costco carries Tyson chicken breasts that are injected with only salt and water, for example. Many of our stores also carry Foster Farms chicken, which also only have salt and water added.