diff --git a/definitions/region/common.yaml b/definitions/region/common.yaml
deleted file mode 100644
index 19895e7..0000000
--- a/definitions/region/common.yaml
+++ /dev/null
@@ -1,2 +0,0 @@
-- common:
-  - World
diff --git a/definitions/variable/variables.yaml b/definitions/variable/variables.yaml
deleted file mode 100644
index e422375..0000000
--- a/definitions/variable/variables.yaml
+++ /dev/null
@@ -1,3 +0,0 @@
-- Emissions|CO2:
-    description: Total net emissions of carbon dioxide (CO2)
-    unit: Mt CO2/yr
diff --git a/nomenclature.yaml b/nomenclature.yaml
index c344d80..20c7265 100644
--- a/nomenclature.yaml
+++ b/nomenclature.yaml
@@ -5,4 +5,25 @@ definitions:
   variable:
     repository: common-definitions
   region:
-    repository: common-definitions
+    repository:
+      name: common-definitions
+      include:
+        - hierarchy: common
+        - hierarchy: R5
+        - hierarchy: R9
+        - hierarchy: R10
+        - hierarchy: G20 Members
+        - hierarchy: MESSAGEix-GLOBIOM 1.1
+        - hierarchy: MESSAGEix-GLOBIOM 1.1-R12
+        - hierarchy: MESSAGEix-GLOBIOM 2.1-R12
+
+mappings:
+  repository:
+    name: common-definitions
+    include:
+      - MESSAGEix-GLOBIOM 1.1
+      - MESSAGEix-GLOBIOM 1.1-BM-R12
+      - MESSAGEix-GLOBIOM 1.1-M-R12
+      - MESSAGEix-GLOBIOM 1.1-MT-R12
+      - MESSAGEix-GLOBIOM 1.1-BMT-R12
+      - MESSAGEix-GLOBIOM 2.1-M-R12