A collection of error, warning, or information messages that result from a system action.

OperationOutcome
issue
A single issue associated with the action
severity
fatal | error | warning | information | success
code
Error or warning code
details
Additional details about the error
diagnostics
Additional diagnostic information about the issue
location
Deprecated: Path of element(s) related to issue
expression
FHIRPath of element(s) related to issue