WARNING: Version 2.1 of Elasticsearch has passed its EOL date.
This documentation is no longer being maintained and may be removed. If you are running this version, we strongly advise you to upgrade. For the latest information, see the current release documentation.
Each mapping type can have custom meta data associated with it. These are not used at all by Elasticsearch, but can be used to store application-specific metadata, such as the class that a document belongs to:
_meta field can be updated on an existing type using the
PUT mapping API.