Expression used to check the data and report a user-friendly message in case that the check fails.

Item Summary
Name	Type	Multiplicity	Description
$itemDefinition.Name.LocalPart	property ExpressionType	[0,1]
$itemDefinition.Name.LocalPart	property LocalizableMessageType	[0,1]	Localizable message that will be displayed to user when the expression check fails.
$itemDefinition.Name.LocalPart	property string	[0,1]

Items
- $itemDefinition.Name.LocalPart
  
  Flags: RAM,runtime
  
  Multiplicity: [0,1]
- $itemDefinition.Name.LocalPart
  
  Flags: RAM,runtime
  
  Multiplicity: [0,1]
  
  Localizable message that will be displayed to user when the expression check fails. This one takes precedence over (non-localizable) failureMessage.
- $itemDefinition.Name.LocalPart
  
  Flags: RAM,runtime
  
  Multiplicity: [0,1]