What is "Code D" in a skilled nursing facility?

A family member stopped by to visit my grandmother today and one of her children mentioned to the family member that my grandmother had signed off on "Code D." She is terminal and refuses hospice and cannot live w/o round the clock care. The nurse would not explain to me, over the phone what is entailed in Code D. It apparently involves no resuscitation but there were other things involved as well such a no IV feeds, food restrictions or not providing on schedule, but doing so only if she requests it. The family member was mentioning a few things that made me wonder if this is some sort of back-door approach to hospice care for those who do not willingly sign on to it. I am surprised she agreed to it as only recently she insisted on signing a DO resuscitate order. She has seemed to have a very strong will to live, and while being realistic, I'd like to see that honored. She has been non-cooperative with some of her pain meds which is interfering w/ the rehab she should be receiving to continue to qualify for rehab. She is getting to the point where she is refusing to eat or eating one bite. She explained to me that she wants to stay in her right mind and be aware of what is happening to her. Any info. or explanation about 'Code D' would be much appreciated.