Allocation deals with the distribution of responsibility for emissions from a production systems that produce more than one final product.
A good example is a dairy cow, who produces milk, calves, meat, and leather. Throughout her life the cow causes emissions of greenhouse gases of various kinds. At the same time, she produces a number of calves, she produces milk, and finally she gets slaughtered which produces meat and leather. The meat in turn consists of higher and lower quality cuts.
There is not one objective truth for how the emissions she caused throughout her life should be allocated between the products. Different allocations can be argued for to answer different questions. The result, unfortunately, is that comparisons of results between different LCA-studies for different products, such as different brands of cheese or milk may give an erroneous conclusions that there are differences where there are none, if the allocations were done differently in the different studies. This can be investigated, of course, but requires work.
All allocations in CarbonData are done according to the same principles for all products, to make them internally fairly comparable.