Development of a FHIR Implementation Guide that provides simple answers to the basic questions that client "consumer" applications developers ask. The project will not only provide guidance to user clients of device-sourced information, but will include FHIR artifacts to streamline the implementation of device informatics integration into applications such as care coordination and decision support. The HL7 Devices WG "Devices on FHIR" project has advanced two FHIR implementation guides, one for hospital-based Point-of-Care Devices (PoCD) and one for home / mobile based Personal Health Devices. (PHD). These both generally target developers of these devices and the information systems that PROVIDE device-sourced content, with all the granular, sometimes confusing detail that may be necessary. For developers of CONSUMING applications this complexity quickly gets in the way of understanding the basics, and implementing the Devices on FHIR approaches. The project's intent is to limit the basic topics to a Top 10 List (notionally) that most developers need answered, including:      * How can a client app determine what device sensor-based information is available for a given individual?      * How can notifications be sent when devices are attached to / detached from a patient?      * How can the device source for a patient observation be determined?      * When does it matter what kind of device and sensor that is used and how is that identified? Note that this FHIR IG will endeavor to minimize the distinction of whether a device is a PHD or PoCD, especially since some use scenarios involve applications that have to integrate data from devices that is at one point from a hospital environment and at others from a home or clinic. For example, a cloud-based CDSS that supports care coordination for a mother with preeclampsia before, during and after delivery. Implementation guidance that is already detailed in either the PHD or PoCD FHIR IGs will be leveraged and referenced in this IG. Note that the PHD FHIR IG also includes a client application focused section that will directly inform this more general device guidance This IG will be developed in collaboration with the HL7-IHE Gemini Device Interoperability program, and will also involve groups such as HL7 Mobile Health WG and others.