The forms in this book include a clause permitting the agent to authorize a donation. If you do not wish to permit organ donations to apply, cross out this paragraph and initial the cross out on the photocopy form you will be signing. You should specifically state whether you would want artificial nutrition and hydration. If you don't want artificial feeding even if discontinuing it could hasten death, this should be specifically stated. Many states will not permit the cessation of nutrition or hydration unless the form specifically authorizes it.
Many religions prohibit it.
The forms in this book permit the withdrawal of nutrition and hydration based on the same criteria as withholding heroic medical efforts. In some states you must separately sign this clause. One difficulty is that it is impossible to know which treatments will be appropriate, necessary, or available. What is heroic in one situation may not be heroic in another. Some forms get quite specific, giving you a complex grid of boxes to check off the types of medical procedures you want or don't want, based on various hypothetical scenarios.