anchor.diff:  ==== Notes
   
   [[find-docs-null-values]]
  -===== Find documents with null values
  -To find documents that contain only `null` values or `[]` in a provided field,
  +===== Find documents missing indexed values
  +To find documents that are missing an indexed value for a field,
   use the `must_not` <<query-dsl-bool-query, boolean query>> with the `exists`
   query.
   
  -The following search returns documents that contain only `null` values or `[]`
  -in the `user` field.
  +The following search returns documents that are missing an indexed value for
  +the `user` field.
   
   [source,js]
   ----
  
positive.code: [[query-dsl-exists-query]]
  === Exists Query
  
  Returns documents that contain a value other than `null` or `[]` in a provided
  field.
  
  [[exists-query-ex-request]]
  ==== Example request
  
negative.code: `field`::
  Name of the field you wish to search.
  +
  While a field is deemed non-existant if the JSON value is `null` or `[]`, these values will indicate the field does exist:
  +
  * Empty strings, such as `""` or `"-"`
  * Arrays containing `null` and another value, such as `[null, "foo"]`
  