diff --git a/abi-versions/vNEXT/README.md b/abi-versions/vNEXT/README.md
index 59748bb..65fed1a 100644
--- a/abi-versions/vNEXT/README.md
+++ b/abi-versions/vNEXT/README.md
@@ -1470,6 +1470,9 @@ gRPC status message can be retrieved using [`proxy_get_status`].
 Sets shared data identified by the key (`key_data`, `key_value`)
 to the value (`value_data`, `value_size`).
 
+If the `value_data` is `0`, then the key (`key_data`, `key_size`) will be
+deleted from the shared key-value store (`kvstore_id`).
+
 If the compare-and-swap value (`cas`) is set to a non-zero value,
 then it must match the host's compare-and-swap value in order for
 the update to succeed.