Change record status: 
Project: 
Introduced in branch: 
8.3.x
Introduced in version: 
8.3.2
Description: 

To better align the migration_lookup process plugin with that it is, it is renamed from 'migration' => 'migration_lookup'. The former process plugin 'migration' is now deprecated and will be removed before 9.x.

There is a backwards compatibility layer so nothing is required to change. However, if you wish to use the new process plugin directly, you'll want to update your migration configuration.

Before:

# d7_contact_settings.yml
   default_form:
    plugin: migration
     migration: contact_category
     source: default_category

After:

# d7_contact_settings.yml
   default_form:
    plugin: migration_lookup
     migration: contact_category
     source: default_category
Impacts: 
Site builders, administrators, editors
Updates Done (doc team, etc.)
Online documentation: 
Not done
Theming guide: 
Not done
Module developer documentation: 
Not done
Examples project: 
Not done
Coder Review: 
Not done
Coder Upgrade: 
Not done
Other: 
Other updates done