The value of a [[QuantitativeValue]] (including [[Observation]]) or property value node.\n\n* For [[QuantitativeValue]] and [[MonetaryAmount]], the recommended type for values is 'Number'.\n* For [[PropertyValue]], it can be 'Text', 'Number', 'Boolean', or 'StructuredValue'.\n* Use values from 0123456789 (Unicode 'DIGIT ZERO' (U+0030) to 'DIGIT NINE' (U+0039)) rather than superficially similar Unicode symbols.\n* Use '.' (Unicode 'FULL STOP' (U+002E)) rather than ',' to indicate a decimal point. Avoid using these symbols as a readability separator.