This data type represents a set of possible values between a low value and a high value. The values are quantities, which may include a unit of measure. The unit of measure is typically going to be the same in the low value and the high value (e.g., 2 years - 5 years, but not necessarily so (e.g., 6 months - 3 years). The low and high values are inclusive (e.g., 2 - 4 tablets allows 2, 3, or 4 tablets). This class was called PhysicalQuantityInterval in the past, in alignment with HL7 V3, but was renamed to Range to align with FHIR. Note that this class used to have four properties: lowValue, lowUnit, highValue, and highUnit, the values being reals and the units being codes. This was similar to the V3 PhysicalQuantityInterval. This has been changed to a low and high, both of type quantity, which is equivalent. "A set of ordered Quantity values defined by a low and high limit." - HL7 FHIR, Range This data type represents an Interval, where the Low and High Limits are Physical Quantities. An Interval is a "set of consecutive values of an ordered base data type." - HL7 V3. A Physical Quantity is "a dimensioned quantity expressing the result of measuring" - HL7 V3