If a SQL Server database is configured with a collation that conflicts with the Locale of the client program, characters that can not be represented in the database's collation are turned into question marks. This was not the behavior prior to version 8.1.2.
Setting this variable to ON, causes all character fields, except those for date fields, to be treated as binary, storing them in the database and retrieving from the database without translation. This provides the behavior seen prior to 8.1.2 and is useful if the client is using a different locale than the database's collation.
The default setting is OFF and means that character fields, except for date fields, will be translated.