Excise value uploading

Hi all

i am uploading Opening and closing balance for BED ECESS, SECESS

through Table J_2IACCBAL

when we create the table entry there are no of field

like

Data element for Register names

Basic duty (OP BAL)

Basic duty (CL BAL)

Basic duty (EXAMT)

Extract Indicator

could any one let me know what is the importance of "Extract Indicator"

and in data element the system doesn't populate the Ecess Register

if anyone let me know that will be highly apriciated