anchor.diff:  
   * In 6.7, the index creation, index template, and mapping APIs support a query
     string parameter (`include_type_name`) which indicates whether requests and
  -  responses should include a type name. It defaults to `true`, and not setting
  -  `include_type_name=false` will result in a deprecation warning. Indices which
  -  don't have an explicit type will use the dummy type name `_doc`.
  +  responses should include a type name. It defaults to `true`, and should be set
  +  to an explicit value to prepare to upgrade to 7.0. Not setting `include_type_name`
  +  will result in a deprecation warning. Indices which don't have an explicit type will
  +  use the dummy type name `_doc`.
   
   Elasticsearch 7.x::
   
  
positive.code:   for auto-generated ids.
  
  * The `include_type_name` parameter in the index creation, index template,
    and mapping APIs will default to `false`. Setting the parameter will result
    in a deprecation warning.
  
  * The `_default_` mapping type is removed.
  
  
negative.code: ==== Indices APIs
  
  Index creation, index template, and mapping APIs support a new `include_type_name`
  URL parameter that specifies whether mapping definitions in requests and responses
  should contain the type name. The parameter defaults to `true` in version 6.7 to
  match the pre-7.0 behavior of using type names in mappings. It defaults to `false`
  in version 7.0 and will be removed in version 8.0.
  
  It should be set explicitly in 6.7 to prepare to upgrade to 7.0. To avoid deprecation
  warnings in 6.7, the parameter can be set to either `true` or `false`. In 7.0, setting
  `include_type_name` at all will result in a deprecation warning.
  
  See some examples of interactions with Elasticsearch with this option set to `false`:
  
  [source,js]
  --------------------------------------------------
  