diff --git a/README.md b/README.md
index 69bb71b..af2b916 100644
--- a/README.md
+++ b/README.md
@@ -150,12 +150,14 @@ everything it sends, in full:
 
 | Field                   | What it is                                        |
 | ----------------------- | ------------------------------------------------- |
-| Licence id              | Which licence this is                             |
+| Product                  | The literal string `jarvis`                        |
+| Licence id               | Which licence this is                              |
 | Instance id + public key | A key pair your instance generated, identifying it |
-| Version                 | Which Jarvis build you are running                |
-| Counts                  | How many organizations, users, agents and assets  |
-| Public URL              | Your instance's address — **optional, see below** |
-| Timestamps              | When the process started, and when it reported    |
+| Version                  | Which Jarvis build you are running                 |
+| Contract version         | Which set of limits this build understands — a checksum, not a document |
+| Counts                   | How many organizations, users, agents and assets   |
+| Public URL               | Your instance's address — **optional, see below**  |
+| Timestamps               | When the process started, and when it reported     |
 
 **Counts, not contents.** No names, no email addresses, no conversation text, no asset inventory, no
 credentials, nothing about what you administer. The only field that identifies your network rather