4d51ede8_rks_Search_UI_2_9___Lucidworks__Description
[Parameter] Multi-Valued [Fields API Attribute Name] multi-valued [Description] 
Enable this if the document could have multiple values for a field, such as multiple categories or authors. We recommend that you reindex all documents after changing this setting.
Field Configuration - LucidWorks Search UI 2.9 - Lucidworks
Description