> curl -X GET --dump - http://localhost:8529/collection/9496015/13658604
HTTP/1.1 200 OK
content-type: application/json
connection: Keep-Alive
server: triagens GmbH High-Performance HTTP Server
etag: "13865832"

{ "Hallo" : "You",
  "_id" : "9496015:13658604"
  "_rev" : 13865832 }

> curl --data @- -X PUT --header 'etag: "13865832"'
>                       --dump - http://localhost:8529/collection/9496015/13658604
{ "Hallo" : "World" }

HTTP/1.1 204 No Content
content-type: text/plain;charset=utf-8
connection: Keep-Alive
server: triagens GmbH High-Performance HTTP Server
etag: "14252313"
content-length: 0

> curl --data @- -X PUT --header 'etag: "13865832"'
>                       --dump - http://localhost:8529/_document/9496015/13658604
{ "Hallo" : "World" }

HTTP/1.1 409 Conflict
content-type: application/json
connection: Keep-Alive
server: triagens GmbH High-Performance HTTP Server

{ "error" : true,
  "message" : "document /collection/9496015/13658604 has been altered",
  "code" : 409 }