Mappings got a feature bump in version 3.0. So it's good to take a look at what has changed since the mappings in version 2.
Mapping input specification
Not much has changed here, except for these 2 things:
- It is now possible to have 0 or more than 1 "Mapping input" step in one and the same mapping.
- It is now possible to let unspecified fields flow through the "mapping input" step with a special option