diff --git a/nomenclature.yaml b/nomenclature.yaml
index ee8e96b..20c7265 100644
--- a/nomenclature.yaml
+++ b/nomenclature.yaml
@@ -12,4 +12,18 @@ definitions:
         - hierarchy: R5
         - hierarchy: R9
         - hierarchy: R10
-        - hierarchy: G20 members
+        - 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