In their paper A Classification of Fracture Classifications Bernstein, Monaghan, Silber and DeLong propose that fracture classification systems be rated according to their ability to match injury categories with treatment categories. A grade A system, in their scheme, has such one-to-one matching. A grade C system is random. A grade B system conceptually links treatment to classification, albeit imperfectly.

A BMSD modificaction of a fracture classification, thus, is a re-arrangement of a grade B (original) classification to yield one of grade A.

One example of a BMSD modification would be simplifying the Garden classification of femoral neck fractures into two categories: displaced and non-displaced. The key criterion of the classification is retained, but the unnecessary division of fracture into four categories is removed ("unnecesaary" in the sense that when there are only two treatments there need not be four categories).