diff --git a/preserves-zerocopy.md b/preserves-zerocopy.md
index b5cf07d..5f0415c 100644
--- a/preserves-zerocopy.md
+++ b/preserves-zerocopy.md
@@ -66,6 +66,58 @@ Either way, the tag on the special `Ref` is the type of the encoded value.
 
 ### Tags and Refs.
 
+    ................................................................
+    Version 1
+
+    00000000 IMM bool
+    ...00100 IMM RESERVED
+    nnn01000 IMM float        nnn = length of payload in bytes. 000 disallowed
+    nnn10000 IMM str
+    nnn10100 IMM bytes
+    nnn11000 IMM sym
+
+    ....1100 IMM int
+
+    .....010     RESERVED
+    ....0110 PTR embedded
+    ....1110 PTR float
+
+    ....0001 PTR str
+    ....0101 PTR bytes
+    ....1001 PTR sym
+    ....1101 PTR int
+
+    ....0011 PTR rec
+    ....0111 PTR seq
+    ....1011 PTR set
+    ....1111 PTR map
+
+    ................................................................
+    Version 2
+
+    0000 0000 IMM bool
+    ...1 0000 IMM RESERVED
+    nnn0 0001 IMM float        nnn = length of payload in bytes. 000 disallowed
+    nnn1 0001 IMM bytes
+    nnn0 0010 IMM str
+    nnn1 0010 IMM sym
+
+    .... 0011 IMM int
+
+    .... 0100 PTR int
+    .... 0101 PTR str
+    .... 0110 PTR bytes
+    .... 0111 PTR sym
+    .... 1000 PTR rec
+    .... 1001 PTR seq
+    .... 1010 PTR set
+    .... 1011 PTR map
+    .... 1100 PTR embedded
+    .... 1101 PTR float
+    .... 1110     RESERVED
+    .... 1111     RESERVED
+
+
     Tag  Type           Interpretation of 60-bit payload
     ---  -------------  --------------------------------
       0  Boolean        0 = False, 1 = True