elasticsearch/docs/reference/mapping/dynamic/default-mapping.asciidoc

[[default-mapping]]
=== `_default_` mapping

deprecated[6.0.0,See <<removal-of-types>>]

The default mapping, which will be used as the base mapping for a new
mapping type, can be customised by adding a mapping type with the name
`_default_` to an index, either when
<<indices-create-index,creating the index>> or later on with the
<<indices-put-mapping,PUT mapping>> API.

The documentation for this feature has been removed as it no longer makes
sense in 6.x where there can be only a single type per index.