anchor.diff:  [[search-rank-eval-api-request]]
   ==== {api-request-title}
   
  -`GET /<index>/_rank_eval`
  -
  -`POST /<index>/_rank_eval`
  +`GET /<target>/_rank_eval`
  +
  +`POST /<target>/_rank_eval`
   
   
   [[search-rank-eval-api-desc]]
  
positive.code: [[search-rank-eval-api-path-params]]
  ==== {api-path-parms-title}
  
  `<index>`::
   (Required, string) Comma-separated list or wildcard expression of index names
   used to limit the request.
  
  [[search-rank-eval-api-query-params]]
  ==== {api-query-parms-title}
  
negative.code: things:
  
  . A collection of documents you want to evaluate your query performance against, 
    usually one or more data streams or indices.
  . A collection of typical search requests that users enter into your system.
  . A set of document ratings that represent the documents' relevance with respect
    to a search request.
  