What ingredients are in poultry seasoning?

Every brand name seasoning is bound to have "special" or "select" spices. However, the earliest cookbooks define poultry seasoning as consisting of only: sage, thyme, marjoram, rosemary, nutmeg and black pepper. The homemade replacement recipe is: 2 teaspoons ground sage 1 1/2 teaspoons ground thyme 1 teaspoon ground marjoram 3/4 teaspoon ground rosemary 1/2 teaspoon nutmeg 1/2 teaspoon finely ground black pepper