What is in "pickling spice"?
It depends on who is mixing/making the spice. I just recently bought some and the ingredients are:
Yellow and brown mustard seeds, cassia buds, allspice, cloves, cracked bay leaves, dill seeds, cracked ginger, Tellicherry peppercorns, star anise, coriander seeds, mace, juniper berries, red chile peppers, cardamom seeds.
It should usually have mustard seeds, bay leaves, pepper at the bare minimum.