anchor.diff:  [[index-noop]]
   === Noop Updates
   
  -When updating a document using the index api a new version of the document is
  +When updating a document using the index API a new version of the document is
   always created even if the document hasn't changed. If this isn't acceptable
  -use the `_update` api with `detect_noop` set to true. This option isn't
  -available on the index api because the index api doesn't fetch the old source
  +use the `_update` API with `detect_noop` set to true. This option isn't
  +available on the index API because the index API doesn't fetch the old source
   and isn't able to compare it against the new source.
   
   There isn't a hard and fast rule about when noop updates aren't acceptable.
   It's a combination of lots of factors like how frequently your data source
   sends updates that are actually noops and how many queries per second
  -Elasticsearch runs on the shard with receiving the updates.
  +Elasticsearch runs on the shard receiving the updates.
   
   [float]
   [[timeout]]
  
positive.code: also supports other types for specific use cases. Here is an overview of
  the different version types and their semantics.
  
  `internal`:: only index the document if the given version is identical to the version
  of the stored document.
  deprecated[6.7.0, Please use `if_seq_no` & `if_primary_term` instead. See <<optimistic-concurrency-control>> for more details.]
  
  
  `external` or `external_gt`:: only index the document if the given version is strictly higher
  than the version of the stored document *or* if there is no existing document. The given
  version will be used as the new version and will be stored with the new document. The supplied
  version must be a non-negative long number.
  
  `external_gte`:: only index the document if the given version is *equal* or higher
  than the version of the stored document. If there is no existing document
  the operation will succeed as well. The given version will be used as the new version
  and will be stored with the new document. The supplied version must be a non-negative long number.
  
negative.code: with each update, deletes included. Optionally, the version number can be
  set to an external value (for example, if maintained in a
  database). To enable this functionality, `version_type` should be set to
  `external`. The value provided must be a numeric, long value greater than or equal to 0,
  and less than around 9.2e+18. 
  
  When using the external version type, the system checks to see if
  