def same_property_kind(pk_a, pk_b):
    """Returns True if the two property kinds are the same, or pseudonyms."""

    if pk_a is None or pk_b is None:
        return False
    if pk_a == pk_b:
        return True
    if pk_a in ['permeability rock', 'rock permeability'] and pk_b in ['permeability rock', 'rock permeability']:
        return True
    return False