anchor.diff:  it searchable. If the target is an index and the document already exists,
   the request updates the document and increments its version.
   
  -NOTE: You cannot send update requests for existing documents to a data stream.
  -To update a document in a data stream, you must target the backing index
  -containing the document. See <<update-delete-docs-in-a-data-stream>>.
  +NOTE: You cannot use the index API to send update requests for existing
  +documents to a data stream. See <<update-delete-docs-in-a-data-stream>>
  +and <<update-delete-docs-in-a-backing-index>>.
   
   [[docs-index-api-request]]
   ==== {api-request-title}
  
positive.code: `PUT /<target>/_create/<_id>`
  
  `POST /<target>/_create/<_id>`
  
  [[docs-index-api-path-params]]
  ==== {api-path-parms-title}
  
negative.code: [float]
  ===== Create document IDs automatically
  
  When using the `POST /<target>/_doc/` request format, the `op_type` is
  automatically set to `create` and the index operation generates a unique ID for
  the document.
  
  [source,console]
  --------------------------------------------------
  