Purpose and effect of $DBNLS env

Hi folks I'm trying to get up to speed with GLS, and I can't seem to do anything which triggers an error contrary to what the GLS manual claims is the purpose of the DBNLS setting: <quote> The DBNLS environment variable specifies whether automatic data type conversion is supported between NCHAR and NVARCHAR database columns and CHAR and VARCHAR variables (respectively) of the client systems. Conversely, setting no value for DBNLS disables automatic conversion between CHAR and VARCHAR variables of the client application and NCHAR and NVARCHAR columns of the database, and also prevents Dynamic Server from using the locale files of the client system: setenv DBNLS unsetenv DBNLS </quote> I've tried using fr_fr.8859-1 locale to create a database and table with CHAR and NCHAR, then tried to operate on it using de_de.8859-1 but I'm not seeing an error when I assign a CHAR to NCHAR or vice- versa in dbaccess. Does the engine or the client require this setting (or both)? What's it supposed to do exactly?