diff --git a/convex-core/src/main/java/convex/core/cvm/Address.java b/convex-core/src/main/java/convex/core/cvm/Address.java
index 19827421d..cb67101a5 100644
--- a/convex-core/src/main/java/convex/core/cvm/Address.java
+++ b/convex-core/src/main/java/convex/core/cvm/Address.java
@@ -8,7 +8,6 @@
 import convex.core.data.Blob;
 import convex.core.data.Format;
 import convex.core.data.Strings;
-import convex.core.data.Tag;
 import convex.core.data.prim.CVMLong;
 import convex.core.data.type.AType;
 import convex.core.data.type.Types;
@@ -191,7 +190,7 @@ public static Address read(Blob b, int pos) throws BadFormatException {
 
 	@Override
 	public int encode(byte[] bs, int pos) {
-		bs[pos++]=Tag.ADDRESS;
+		bs[pos++]=CVMTag.ADDRESS;
 		return encodeRaw(bs,pos);
 	}
 	
@@ -234,7 +233,7 @@ public Blob toFlatBlob() {
 
 	@Override
 	public byte getTag() {
-		return Tag.ADDRESS;
+		return CVMTag.ADDRESS;
 	}
 
 	@Override
diff --git a/convex-core/src/main/java/convex/core/cvm/CVMTag.java b/convex-core/src/main/java/convex/core/cvm/CVMTag.java
new file mode 100644
index 000000000..503c8db0e
--- /dev/null
+++ b/convex-core/src/main/java/convex/core/cvm/CVMTag.java
@@ -0,0 +1,23 @@
+package convex.core.cvm;
+
+/**
+ * Class defining tags for CVM CAD3 extension types
+ */
+public class CVMTag {
+
+	/**
+	 * Tag for Convex Address type
+	 */
+	public static final byte ADDRESS = (byte) 0xEA;
+	
+	/**
+	 *  CVM Core definitions
+	 */
+	public static final byte CORE_DEF = (byte) 0xED;
+	
+	/**
+	 *  Special Ops
+	 */
+	public static final byte SPECIAL_OP = (byte) 0xE5;
+
+}
diff --git a/convex-core/src/main/java/convex/core/data/CAD3Encoder.java b/convex-core/src/main/java/convex/core/data/CAD3Encoder.java
index 951a357df..689b47503 100644
--- a/convex-core/src/main/java/convex/core/data/CAD3Encoder.java
+++ b/convex-core/src/main/java/convex/core/data/CAD3Encoder.java
@@ -1,6 +1,7 @@
 package convex.core.data;
 
 import convex.core.cvm.Address;
+import convex.core.cvm.CVMTag;
 import convex.core.data.prim.AByteFlag;
 import convex.core.data.prim.ANumeric;
 import convex.core.data.prim.CVMBigInteger;
@@ -44,7 +45,7 @@ protected ACell read(byte tag, Blob encoding, int offset) throws BadFormatExcept
 			return readNumeric(tag,encoding,offset);
 			
 		case 2: // 0x20-0x2F : Addresses and references 
-			if (tag == Tag.ADDRESS) return Address.read(encoding,offset);
+			if (tag == CVMTag.ADDRESS) return Address.read(encoding,offset);
 			// Note: 0x20 reference is invalid as a top level encoding
 			break;
 
diff --git a/convex-core/src/main/java/convex/core/data/CVMEncoder.java b/convex-core/src/main/java/convex/core/data/CVMEncoder.java
index 2f5fcbfa4..b2e0af8b1 100644
--- a/convex-core/src/main/java/convex/core/data/CVMEncoder.java
+++ b/convex-core/src/main/java/convex/core/data/CVMEncoder.java
@@ -1,5 +1,7 @@
 package convex.core.data;
 
+import convex.core.cvm.Address;
+import convex.core.cvm.CVMTag;
 import convex.core.exceptions.BadFormatException;
 import convex.core.lang.Core;
 
@@ -18,7 +20,8 @@ public ACell read(Blob encoding,int offset) throws BadFormatException {
 	protected ACell readExtension(byte tag, Blob blob, int offset) throws BadFormatException {
 		// We expect a VLQ Count following the tag
 		long code=Format.readVLQCount(blob,offset+1);
-		if (tag == Tag.CORE_DEF) return Core.fromCode(code);
+		if (tag == CVMTag.CORE_DEF) return Core.fromCode(code);
+		if (tag == CVMTag.ADDRESS) return Address.create(code);
 		
 		return ExtensionValue.create(tag, code);
 	}
diff --git a/convex-core/src/main/java/convex/core/data/Format.java b/convex-core/src/main/java/convex/core/data/Format.java
index 108cc82c9..3ef80fab9 100644
--- a/convex-core/src/main/java/convex/core/data/Format.java
+++ b/convex-core/src/main/java/convex/core/data/Format.java
@@ -16,6 +16,7 @@
 import convex.core.cvm.AFn;
 import convex.core.cvm.AccountStatus;
 import convex.core.cvm.Address;
+import convex.core.cvm.CVMTag;
 import convex.core.cvm.Ops;
 import convex.core.cvm.PeerStatus;
 import convex.core.cvm.Receipt;
@@ -518,7 +519,7 @@ private static ACell readExtension(byte tag, Blob blob, int offset) throws BadFo
 		// We expect a VLQ Count following the tag
 		long code=readVLQCount(blob,offset+1);
 		
-		if (tag == Tag.CORE_DEF) return Core.fromCode(code);
+		if (tag == CVMTag.CORE_DEF) return Core.fromCode(code);
 	
 		return ExtensionValue.create(tag, code);
 	}
@@ -594,7 +595,7 @@ static <T extends ACell> T read(byte tag, Blob blob, int offset) throws BadForma
 			
 			if (high == 0x30) return (T) readBasicObject(tag,blob,offset);
 			
-			if (tag == Tag.ADDRESS) return (T) Address.read(blob,offset);
+			if (tag == CVMTag.ADDRESS) return (T) Address.read(blob,offset);
 			
 			if (high == 0xB0) return (T) AByteFlag.read(tag);
 			
diff --git a/convex-core/src/main/java/convex/core/data/Tag.java b/convex-core/src/main/java/convex/core/data/Tag.java
index 537ac9f9c..c2d3d781b 100644
--- a/convex-core/src/main/java/convex/core/data/Tag.java
+++ b/convex-core/src/main/java/convex/core/data/Tag.java
@@ -30,7 +30,7 @@ public class Tag {
 
 	// crypto and security primitives
 	public static final byte REF = (byte) 0x20;
-	public static final byte ADDRESS = (byte) 0x21;
+	
 
 	// =========================================
 	// Strings and Blobs (0x3x)
@@ -121,13 +121,6 @@ public class Tag {
 
 	public static final byte EXTENSION_VALUE_BASE = (byte) 0xE0;
 
-	// CVM Core definitions
-	public static final byte CORE_DEF = (byte) 0xED;
-	
-	// Special Ops
-	public static final byte SPECIAL_OP = (byte) 0xE5;
-
-
 	//===========================================
 	// Illegal / reserved for special values (0xFx)
 	public static final byte ILLEGAL = (byte) 0xFF;
diff --git a/convex-core/src/main/java/convex/core/lang/impl/CoreFn.java b/convex-core/src/main/java/convex/core/lang/impl/CoreFn.java
index 0056207a6..c0ec6c830 100644
--- a/convex-core/src/main/java/convex/core/lang/impl/CoreFn.java
+++ b/convex-core/src/main/java/convex/core/lang/impl/CoreFn.java
@@ -1,13 +1,13 @@
 package convex.core.lang.impl;
 
 import convex.core.cvm.AFn;
+import convex.core.cvm.CVMTag;
 import convex.core.cvm.Context;
 import convex.core.data.ACell;
 import convex.core.data.Format;
 import convex.core.data.IRefFunction;
 import convex.core.data.Ref;
 import convex.core.data.Symbol;
-import convex.core.data.Tag;
 import convex.core.data.util.BlobBuilder;
 import convex.core.exceptions.InvalidDataException;
 
@@ -47,7 +47,7 @@ public Symbol getIntrinsicSymbol() {
 	}
 	
 	public byte getTag() {
-		return Tag.CORE_DEF;
+		return CVMTag.CORE_DEF;
 	}
 
 	protected String name() {
@@ -94,7 +94,7 @@ public boolean print(BlobBuilder sb, long limit) {
 
 	@Override
 	public int encode(byte[] bs, int pos) {
-		bs[pos++]=Tag.CORE_DEF;
+		bs[pos++]=CVMTag.CORE_DEF;
 		return encodeRaw(bs,pos);
 	}
 
diff --git a/convex-core/src/test/java/convex/core/data/AddressTest.java b/convex-core/src/test/java/convex/core/cvm/AddressTest.java
similarity index 74%
rename from convex-core/src/test/java/convex/core/data/AddressTest.java
rename to convex-core/src/test/java/convex/core/cvm/AddressTest.java
index 80c7662f7..35d7cad6a 100644
--- a/convex-core/src/test/java/convex/core/data/AddressTest.java
+++ b/convex-core/src/test/java/convex/core/cvm/AddressTest.java
@@ -1,4 +1,4 @@
-package convex.core.data;
+package convex.core.cvm;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNull;
@@ -6,7 +6,14 @@
 
 import org.junit.jupiter.api.Test;
 
-import convex.core.cvm.Address;
+import convex.core.data.ACell;
+import convex.core.data.Blob;
+import convex.core.data.Blobs;
+import convex.core.data.BlobsTest;
+import convex.core.data.Format;
+import convex.core.data.ObjectsTest;
+import convex.core.exceptions.BadFormatException;
+import convex.core.util.Utils;
 
 public class AddressTest {
 
@@ -27,6 +34,16 @@ public void testAddress2() {
 		assertEquals("#13",a1.toString());
 	}
 	
+	@Test
+	public void testEncoding() throws BadFormatException {
+		Address a= Address.create(17);
+		Blob enc=a.getEncoding();
+		assertEquals(Utils.toHexString(CVMTag.ADDRESS)+"11",enc.toHexString());
+		ACell ra=Format.read(enc);
+		assertTrue(ra instanceof Address);
+		assertEquals(a,ra);
+	}
+	
 	@Test
 	public void testParse() {
 		assertEquals("#1",Address.parse("#1").toString());
diff --git a/convex-core/src/test/java/convex/core/data/CAD3Test.java b/convex-core/src/test/java/convex/core/data/CAD3Test.java
index 1ccebe29a..d0430f1c2 100644
--- a/convex-core/src/test/java/convex/core/data/CAD3Test.java
+++ b/convex-core/src/test/java/convex/core/data/CAD3Test.java
@@ -11,6 +11,7 @@
 import org.junit.jupiter.api.TestInstance.Lifecycle;
 
 import convex.core.cvm.Address;
+import convex.core.cvm.CVMTag;
 import convex.core.cvm.Context;
 import convex.core.data.prim.CVMLong;
 import convex.core.lang.ACVMTest;
@@ -34,11 +35,11 @@ public class CAD3Test extends ACVMTest {
 	}
 	
 	@Test public void testExtensionCoreDefs() {
-		assertSame(Core.VECTOR,Reader.read("#["+Utils.toHexString(Tag.CORE_DEF)+"01]"));
+		assertSame(Core.VECTOR,Reader.read("#["+Utils.toHexString(CVMTag.CORE_DEF)+"01]"));
 	}
 	
 	@Test public void testReadEncodings() {
-		assertSame(Address.ZERO,Reader.read("#[2100]"));
+		assertSame(Address.ZERO,Reader.read("#[EA00]"));
 		assertSame(CVMLong.ZERO,Reader.read("#[10]"));
 		assertSame(Vectors.empty(),Reader.read("#[8000]"));
 		assertNull(Reader.read("#[00]"));