diff --git a/OpenAPI.yaml b/OpenAPI.yaml
index 56e161e914adbc727e10227bda48d2f114c6fc75..2b1f08bf1e9ecfe600a9cf857ff01dc88673929c 100644
--- a/OpenAPI.yaml
+++ b/OpenAPI.yaml
@@ -544,49 +544,49 @@ components:
           example : "1.01"
 
     Transform3D:
-        description: Coordinate reference system of the world anchor, a 4*4 matrix (rowmajor) represented by a float vector
-        type: array
-        minItems: 16
-        maxItems: 16
-        items:
-            type: number
-            format: float
-        example: [-2,  1,  -3, 4,
-                    4,   4,  4,  2,
-                    1,   0,  -2, 1,
-                    -1,  -2, 0,  0]
+      description: Coordinate reference system of the world anchor, a 4*4 matrix (rowmajor) represented by a float vector
+      type: array
+      minItems: 16
+      maxItems: 16
+      items:
+        type: number
+        format: float
+      example: [-2,  1,  -3, 4,
+                4,   4,  4,  2,
+                1,   0,  -2, 1,
+                -1,  -2, 0,  0]
 
     ObjectType:
-        description: Type of an world representaion object.
-        type: string
-        enum: [Trackable, WorldAnchor, WorldLink]
-        example: Trackable
+      description: Type of an world representaion object.
+      type: string
+      enum: [Trackable, WorldAnchor, WorldLink]
+      example: Trackable
 
     UnitSystem:
-        description: Unit of length.
-        type: string
-        enum: [MM,  CM,  DM,  M,  DAM,  HM,  KM,  INCH, FOOT, YARD, MILE]
-        example: M
+      description: Unit of length.
+      type: string
+      enum: [MM,  CM,  DM,  M,  DAM,  HM,  KM,  INCH, FOOT, YARD, MILE]
+      example: M
 
     Size:
-        description: Size {width, length, depth}.
-        type: array
-        items:
-            type: number
-            format: double
-        minItems: 3
-        maxItems: 3
-        example: [1,5,0]
+      description: Size {width, length, depth}.
+      type: array
+      items:
+        type: number
+        format: double
+      minItems: 3
+      maxItems: 3
+      example: [1,5,0]
 
     KeyvalueTagList:   
-        description: List of additional parameters to be stored with the trackable.
-        type: object
-        additionalProperties:
-            type: array
-            items:
-                type: string
-            minItems: 1
-        example: { "Place" : ["Museum 1"], "room" : ["B4"]} 
+      description: List of additional parameters to be stored with the trackable.
+      type: object
+      additionalProperties:
+        type: array
+        items:
+          type: string
+        minItems: 1
+      example: { "Place" : ["Museum 1"], "room" : ["B4"]} 
 
     Error:
       required: