diff --git a/gitbook-docs/SUMMARY.md b/gitbook-docs/SUMMARY.md
index 7fe7616cb..110faf90c 100644
--- a/gitbook-docs/SUMMARY.md
+++ b/gitbook-docs/SUMMARY.md
@@ -16,6 +16,7 @@
   * [Subscription Protocol](subscription_protocol.md)
   * [Discovery & Connection Establishment](connection.md)
   * [Notifications](notifications.md)
+  * [PUT Requests](put.md)
 * [How Can I Help?](how_to_help.md)
 * [Appendix A: Keys Reference (Vessel)](vesselsBranch.md)
 * [Appendix B: Keys Reference (Others)](otherBranches.md)
diff --git a/gitbook-docs/put.md b/gitbook-docs/put.md
new file mode 100644
index 000000000..603b18c33
--- /dev/null
+++ b/gitbook-docs/put.md
@@ -0,0 +1,108 @@
+# PUT Requests
+
+PUT requests are sent to a server to request a change to a value. For example, a client would use PUT to switch the
+anchor light on or off, change the heading of the autopilot, or set position of the anchor.
+
+See [Request/Response](request_response.md) for more details on request/response in Signal K.
+
+## Making a Request to Change a Value
+
+To change a value, a PUT request should be sent via HTTP or using a Signal K __put__ delta.
+
+The `source` field is optional. If a request is sent without the source and there is more than one source for the
+value, the server should respond with a 400 (Bad Request) HTTP status code.
+
+### Via HTTP
+```
+PUT http://localhost:3000/signalk/v1/api/vessels/self/steering/autopilot/target/headingTrue
+{
+  "value": 1.52,
+  "source": "actisense.204",
+}
+```
+
+### Via a Delta
+```json
+{
+  "context": "vessels.self",
+  "correlationId": "184743-434373-348483",
+  "put": {
+    "path": "steering.autopilot.target.headingTrue",
+    "source": "actisense.204",
+    "value": 1.52
+  }
+}
+```
+
+### HTTP Error Response
+
+HTTP response code 403 (Forbidden)
+
+JSON response body:
+```json
+{
+  "state": "COMPLETED",
+  "statusCode": 403
+}
+```
+
+### HTTP Success Response
+
+HTTP response code 200 (OK)
+
+JSON response body:
+```json
+{
+  "state": "COMPLETED",
+  "statusCode": 200
+}
+```
+
+### HTTP Success Response Indicating a Long Running Task
+
+The response in this case includes an optional `href` that can be used to check the status of the request.
+
+HTTP response code 202 (Accepted)
+
+JSON response body:
+```json
+{
+  "state": "PENDING",
+  "href": "/signalk/v1/actions/12567"
+}
+```
+
+A client may periodically GET the URL provided above to check the status of the request.
+
+#### Response Indicating Successful Completion
+
+```json
+{
+   "context": "vessels.self",
+   "state": "COMPLETED",
+   "statusCode": 200,
+}
+```
+
+#### Response Indicating Failure
+
+```json
+{
+   "context": "vessels.self",
+   "state": "COMPLETED",
+   "statusCode": 502,
+   "message": "Unable to reach device",
+}
+```
+
+#### Response Indicating Process is in Progress
+
+_Note:_ `progress` is optional and is specified as a ratio (a number from zero to one)
+
+```json
+{
+   "context": "vessels.self",
+   "state": "PENDING",
+   "progress": 0.45
+}
+```