noteAn optional element for when the clinical user wishes to provide supporting textual information for the allergy record that cannot be conveyed within other elements of the resource.
Where a provider system only has the capability to record a note at one level it SHOULD populate the AllergyIntolerance.note elements with any notes data captured within the system, irrespective of the data level that the system uses to capture that data.
Where a provider system has the capability to record a note at both the AllergyIntolerance and at the AllergyIntolerance.reaction level it SHOULD populate both with the relevant notes applicable to each level.
Consumer systems SHALL be able to handle both multiple AllergyIntolerance.note and multiple AllergyIntolerance.reaction.note elements.