This section details how to restrict search indexes to particular languages.
You do this by generating a partition using the "Assign Languages" tab of the
"Partition Indexes" view.
To add a new language to partition by, use the "Assign Languages" tab to build
an index for it. Select the desired language from the "Language to add"
pull-down list and click "Add Language".
To remove a language, select it from the "Language Selection" list and click
"Remove Language".
To set the default language, select it from the list and click "Set Default".