diff --git a/Messaging-Client.md b/Messaging-Client.md
index 580e539..f7495f3 100644
--- a/Messaging-Client.md
+++ b/Messaging-Client.md
@@ -1,14 +1,16 @@
 The messaging client is a [BSP client](BSP) that synchronises private messages between pairs of devices.
 
-### Group identifiers
+### Identifier
 
-The client's identifier is `org.briarproject.briar.messaging`.
+The client's identifier is `org.briarproject.briar.messaging`. The major version is 0.
 
-The client uses a separate group for each pair of contacts. The [group descriptor](BSP#group-identifiers) is a [BDF list](BDF) containing the unique IDs of the contacts' identities, sorted in ascending order as byte strings.
+### Groups
+
+The client uses a separate BSP group for communicating with each contact. The [group descriptor](BSP#group-identifiers) is a [BDF list](BDF) containing the unique IDs of the contacts' identities, sorted in ascending order as byte strings.
 
 ### Message types
 
-**PRIVATE_MESSAGE** - The message body is a BDF list with one: `content` (string).
+**PRIVATE_MESSAGE** - The message body is a BDF list with one element: `content` (string).
 
 ### Validity policy