diff --git a/OperationDefinition/OperationDefinition-prescription-release.xml b/OperationDefinition/OperationDefinition-prescription-release.xml
index 63484342..2c81caa5 100644
--- a/OperationDefinition/OperationDefinition-prescription-release.xml
+++ b/OperationDefinition/OperationDefinition-prescription-release.xml
@@ -51,9 +51,9 @@
     <parameter>
         <name value="agent"></name>
         <use value="in"></use>
-        <min value="1"></min>
+        <min value="0"></min>
         <max value="1"></max>
-        <documentation value="The professional submitting the release request"></documentation>
+        <documentation value="The professional submitting the release request, required for user-initiated release requests, omitted for unattended requests"></documentation>
         <type value="PractitionerRole"></type>
     </parameter>
     <parameter>
@@ -72,4 +72,4 @@
         <documentation value="A FHIR Bundle (type=collection) which contains OperationOutcome resources for each Prescription failing signature verification which matches the search parameters."></documentation>
         <type value="Bundle"></type>
     </parameter>
-</OperationDefinition>
\ No newline at end of file
+</OperationDefinition>