diff --git a/status-whisper-usage-spec.md b/status-whisper-usage-spec.md
index df5d6f1..156a569 100644
--- a/status-whisper-usage-spec.md
+++ b/status-whisper-usage-spec.md
@@ -18,7 +18,9 @@
     - [One-to-one topic](#one-to-one-topic)
     - [Group chat topic](#group-chat-topic)
   - [Message encryption](#message-encryption)
-  - [Whisper V6 extensions (or Status Whisper Node)](#whisper-v6-extensions-or-status-whisper-node)
+  - [Whisper V6 extensions](#whisper-v6-extensions)
+    - [Request historic messages](#request-historic-messages)
+      - [shhext_requestMessages](#shhextrequestmessages)
 
 ## Abstract
 
@@ -173,8 +175,29 @@ Public and group messages are encrypted using symmetric encryption and the key i
 
 One-to-one messages are encrypted using asymmetric encryption.
 
-## Whisper V6 extensions (or Status Whisper Node)
+## Whisper V6 extensions
 
-TOODO
+### Request historic messages
 
-<!--TODO: provide a list of required JSON-RPC methods, if any -->
+Sends a request for historic messages to a Mailserver. The Mailserver node MUST be a direct peer and MUST be marked a trusted (using `shh_markTrustedPeer`).
+
+The request does not wait for the response. It marely sends a peer-to-peer message to the Mailserver and it's up to Mailserver to process it and start sending historic messages.
+
+The drawback of this approach is that it is impossible to tell which historic messages are the result of which request.
+
+It's recommended to return messages from newest to oldest. To move further back in time, use `cursor` and `limit`.
+
+#### shhext_requestMessages
+
+**Parameters**:
+1. Object - The message request object:
+* `mailServerPeer` - `String`: Mailserver's enode address.
+* `from` - `Number` (optional): Lower bound of time range as unix timestamp, default is 24 hours back from now.
+* `to` - `Number` (optional): Upper bound of time range as unix timestamp, default is now.
+* `limit` - `Number` (optional): Limit the number of messages sent back, default is no limit.
+* `cursor` - `String` (optional): Used for paginated requests.
+* `topics` - `Array`: hex-encoded message topics.
+* `symKeyID` - `String`: an ID of a symmetric key to authenticate to Mailserver, derived from Mailserver password.
+
+**Returns**:
+`Boolean` - returns `true` if the request was sent.