diff --git a/org/open_power/Common/Callout.errors.yaml b/org/open_power/Common/Callout.errors.yaml
new file mode 100644
index 0000000..dab7a3b
--- /dev/null
+++ b/org/open_power/Common/Callout.errors.yaml
@@ -0,0 +1,2 @@
+- name: Procedure
+  description: Procedure callout
diff --git a/org/open_power/Common/Callout.metadata.yaml b/org/open_power/Common/Callout.metadata.yaml
new file mode 100644
index 0000000..00e2067
--- /dev/null
+++ b/org/open_power/Common/Callout.metadata.yaml
@@ -0,0 +1,4 @@
+- name: Procedure
+  meta:
+    - str: "PROCEDURE=%u"
+      type: uint32
diff --git a/org/open_power/Host.errors.yaml b/org/open_power/Host.errors.yaml
index c48f3ed..ab3df62 100644
--- a/org/open_power/Host.errors.yaml
+++ b/org/open_power/Host.errors.yaml
@@ -1,2 +1,5 @@
 - name: Event
   description: A host system event was received
+
+- name: MaintenanceProcedure
+  description: A host system event with a procedure callout
diff --git a/org/open_power/Host.metadata.yaml b/org/open_power/Host.metadata.yaml
index 125f397..8fd8870 100644
--- a/org/open_power/Host.metadata.yaml
+++ b/org/open_power/Host.metadata.yaml
@@ -5,3 +5,11 @@
       type: string
   inherits:
     - xyz.openbmc_project.Common.Callout.Inventory
+
+- name: MaintenanceProcedure
+  level: ERR
+  meta:
+    - str: "ESEL=%s"
+      type: string
+  inherits:
+    - org.open_power.Common.Callout.Procedure