this booklet was developed to assist manufacturers as they write lay user instructions for medical devices used in home health care. the goal of the booklet is to help assure that all users of medical devices used in home health care have readable and understandable instructions in order to operate these devices safely and effectively. it includes, and is intended to be a model of, principles of writing and design. these recommendations cover both content and format. they include:planning a user instruction manual, writing instructions, writing warnings, and designing and testing the manual.