This help book in the User's Guide book covers the following information:

dBASE Plus assigns a language driver to a table automatically when you create it.  This assignment is recorded in the LDID, a 1-byte identifier in the file header region.  When you create a table from scratch, dBASE Plus always assigns the current global language driver to the LDID.  When you create a table file from another table file, either the global language driver or the language driver of the original table is assigned to the LDID of the new table.