diff --git a/.gitignore b/.gitignore
index 1e79a01..f7c61bf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 cic.json
+out
diff --git a/Makefile b/Makefile
index d41005b..3a3a034 100644
--- a/Makefile
+++ b/Makefile
@@ -5,4 +5,5 @@ build:
 
 
 test: build
-	check-jsonschema --schemafile cic.json test_valid.json
+	check-jsonschema --schemafile out/cic.json test_valid.json
+	check-jsonschema --schemafile out/voucher.json test_valid.json
diff --git a/bundle.py b/bundle.py
index 7eedf78..eb6c199 100644
--- a/bundle.py
+++ b/bundle.py
@@ -35,4 +35,23 @@ for k in o_nft['properties'].keys():
     o['properties'][k] = p
 
 
-print(json.dumps(o))
+os.makedirs('out', exist_ok=True)
+
+fp = os.path.join('out', 'cic.json')
+f = open(fp, 'w')
+json.dump(o, f)
+f.close()
+
+fp = os.path.join('.', 'voucher.in.json')
+f = open(fp, 'r')
+o_voucher = json.load(f)
+for k in o_voucher['properties'].keys():
+    p = {}
+    for v in o_voucher['properties'][k]:
+            p[v] = o_voucher['properties'][k][v]
+    o['properties'][k] = p
+
+fp = os.path.join('out', 'voucher.json')
+f = open(fp, 'w')
+json.dump(o, f)
+f.close()
diff --git a/cic.in.json b/cic.in.json
index 6b92702..4655496 100644
--- a/cic.in.json
+++ b/cic.in.json
@@ -1,10 +1,21 @@
 {
 	"$schema": "https://json-schema.org/draft/2020-12/schema",
-	"$id": "sha256:",
 	"title": "CIC core metadata container",
+	"$id": "/cic/core",
 
 	"type": "object",
 	"properties": {
+		"version": {
+			"type": "integer"
+		},
+		"validFrom": {
+			"type": "string",
+			"format": "date-time"
+		},
+		"validUntil": {
+			"type": "string",
+			"format": "date-time"
+		},
 		"targets": {
 			"type": "array",
 			"items": {
@@ -27,5 +38,5 @@
 			}
 		}
 	},
-	"required": ["targets", "attachments", "txs"]
+	"required": ["targets", "attachments", "txs", "validFrom"]
 }
diff --git a/mime.in.json b/mime.in.json
index ec18a85..440e1d2 100644
--- a/mime.in.json
+++ b/mime.in.json
@@ -20,7 +20,19 @@
 		"body": {
 			"type": "string",
 			"$comment": "uri including dataurl"
+		},
+		"ref": {
+			"type": "string",
+			"format": "uri"
 		}
 	},
-	"required": ["contentType", "body", "subject"]
+	"required": ["contentType", "subject"],
+	"oneOf": [
+		{
+			"required": ["body"]
+		},
+		{
+			"required": ["ref"]
+		}
+	]
 }
diff --git a/test_valid.json b/test_valid.json
index 46f527b..c4892ee 100644
--- a/test_valid.json
+++ b/test_valid.json
@@ -5,6 +5,10 @@
 		"0xabcdef0123456789abcdef0123456789abcdef00",
 		"abcdef0123456789abcdef0123456789abcdef00"
 	],
+	"validFrom": "2023-03-05T10:46:05+00:00",
+	"validUntil": "2024-03-05T10:46:05+00:00",
+	"unitOfAccount": "wampum",
+	"issuerName": "John Doe",
 	"txs": [
 		"0xabcdef0123456789abcdef0123456789abcdef00abcdef0123456789abcdef00",
 		"abcdef0123456789abcdef0123456789abcdef00abcdef0123456789abcdef00"
@@ -20,6 +24,12 @@
 			"subject": "some text",
 			"body": "fee fi fo fum"
 		},
+		{
+			"contentType": "text/plain",
+			"contentTransferEncoding": "7BIT",
+			"subject": "some text",
+			"ref": "sha256:2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae"
+		},
 		{
 			"contentType": "application/pdf",
 			"contentTransferEncoding": "BASE64",
diff --git a/voucher.in.json b/voucher.in.json
new file mode 100644
index 0000000..380b882
--- /dev/null
+++ b/voucher.in.json
@@ -0,0 +1,19 @@
+{
+	"$schema": "https://json-schema.org/draft/2020-12/schema",
+	"$id": "/cic/voucher",
+	"title": "CIC voucher schema extensiom",
+
+	"type": "object",
+	"properties": {
+		"unitOfAccount": {
+			"type": "string"
+		},
+		"issuerName": {
+			"type": "string"
+		},
+		"namespace": {
+			"type": "string"
+		}
+	},
+	"require": ["unitOfAccount", "issuerName"]
+}