The index segment casing.
SQL Drivers (SQL Server, DB2 and ODBC)
Used, Ignored
DF_INDEX_SEGMENT_CASE (enum list)
The keyword indicates if the segment is case insensitive. Case insensitive segments treat every value as if it were stored in one casing (uppercase). Trying to add the values "Data Access" and "data access" to a column that is the single case insensitive segment in a one-segment index will result in a duplicate record error.
Setting the keyword to "Used" will make the segment case sensitive (no duplicate record error would be generated in the above example). Setting the keyword to "Ignored" will make the segment case insensitive and behave like the example above.