diff --git a/source/structure/r1.sindri.json b/source/structure/r1.sindri.json
index 7ec6440..c949a22 100644
--- a/source/structure/r1.sindri.json
+++ b/source/structure/r1.sindri.json
@@ -11,7 +11,8 @@
 				{
 					"name": "data",
 					"type": "string_long",
-					"nullable": false
+					"nullable": false,
+					"description": "JSON"
 				}
 			],
 			"constraints": [
@@ -33,9 +34,20 @@
 					"name": "name",
 					"type": "string_medium",
 					"nullable": false
+				},
+				{
+					"name": "email_address",
+					"type": "string_medium",
+					"nullable": true
 				}
 			],
 			"constraints": [
+				{
+					"kind": "unique",
+					"parameters": {
+						"fields": ["name"]
+					}
+				}
 			]
 		},
 		{