Under what circumstances should development costs be excluded in determining DD&A? Under what circumstances should a portion of proved developed reserves be excluded in determining DD&A? Is the exclusion of the development costs or proved developed reserves dependent upon the choice of the company, r is it required? 4. Under what circumstances should development costs be excluded in determining DD&A? Under what circumstances should a portion of proved developed reserves be excluded in determining DD&A? Is the exclusion of the development costs or proved developed reserves dependent upon the choice of the company, r is it required? 4