Information in the header portion of the measure is descriptive in nature and summarizes the measure in a more human readable fashion. Information in the body of the measure is definitional in nature and provides the definitive logic for processing the measure. Thus, the more precise timing statement “Occurrence A of Encounter, Performed: Emergency Department Visit" during "Measurement Period” from the body of the measure definition should be taken as the definition.   In the 2016 Annual Update, the language for the description of the Initial Population and the Measure Population will be modified to more accurately reflect the timing logic present in the measure’s definition.