If the field is set to 'Y', then SPEED II will act as it did in Release 7.0. If set to 'N', then it will treat the character as an underlined character 00-1F, which is how Release 6.x and below worked.
This new field was added as part of the fix for ECR 3820. International sites will probably want to set this field to 'N'. Remember that changes to values in Installation Configuration do not take effect until SPEED II is restarted.
If your site uses any special security classes or you have set priorities on the different function processors, you will need to make these changes again. If you have any Rights programs, you will need to recreate them under Release 7 and then reassign the special security privileges to them.
Design files which have been converted to Release 7 (or applications which have been developed using Release 7) can be downgraded to Release 6 by using the Restructure Files selection in Design File Management. SPEED II will not allow you to enter Application Design with design files in the wrong format. If you want to downgrade you must use EZPATCH (in library '$') to change the 00000000 file in the library '$$vvaaa1' (where vv = version and aaa = application id). You need to change the '7' at position 4 to a '6'.