4d51ede8_rks_Search_UI_2_9___Lucidworks__Description
[Parameter] Index for Auto-complete [Fields API Attribute Name] index_for_autocomplete [Description] 
This allows terms from this field to be used in creation of an auto-complete index that will be created by default at the time of indexing. All fields selected for use in auto-complete are combined into a single "autocomplete" field for use in search suggestions. If you change this setting, we recommend that you recreate the auto-complete index as described in Auto-Complete of User Queries.
Field Configuration - LucidWorks Search UI 2.9 - Lucidworks
Description