diff --git a/yaml/org/open_power/Logging/PEL/Entry.interface.yaml b/yaml/org/open_power/Logging/PEL/Entry.interface.yaml
index 06f4dee..0ea6ba9 100644
--- a/yaml/org/open_power/Logging/PEL/Entry.interface.yaml
+++ b/yaml/org/open_power/Logging/PEL/Entry.interface.yaml
@@ -1,15 +1,21 @@
-description: >
-    Implement to provide PEL event/error entry attributes.
-properties:
-    - name: Hidden
-      type: boolean
-      default: false
-      description: >
-          Hidden Error - This flag allows events to be placed in a system, but
-          remain hidden from the customer. This event log is visible to
-          development personnel only, e.g. hardware recovered error, etc. No
-          service action is required for this type of errors. In general, when
-          this value is used, the Error Action Flags has the value of
-          "Hidden Error". An event log with this value is used primarily for
-          error thresholding design/code debug or as a record to indicate an
-          error frequency or trend.
+description: >
+    Implement to provide PEL event/error entry attributes.
+properties:
+    - name: Hidden
+      type: boolean
+      default: false
+      description: >
+        Hidden Error - This flag allows events to be placed in a system, but
+        remain hidden from the customer. This event log is visible to
+        development personnel only, e.g. hardware recovered error, etc. No
+        service action is required for this type of errors. In general, when
+        this value is used, the Error Action Flags has the value of
+        "Hidden Error". An event log with this value is used primarily for
+        error thresholding design/code debug or as a record to indicate an
+        error frequency or trend.
+    - name: Subsystem
+      type: string
+      description: >
+        A free form, implementation defined string which uniquely and
+        permanently identifies a specific subsystem string. This field should
+        not be used for programmatic interrogation of an object.