J1INCUST - Enter Certificate

Hi Friends

Can anybody explain what is the use of J1INCUST - Enter Certificate. I have tried the Transaction, after posting the Certificate getting an entry like this

Dr 102010 250000( Account Manually assigned for Testing)

Cr 113131 250000( Bank Clearing Account)

I am confused with this entry , the purpose of using the transaction is to Make adjustment entry for the Tax deducted by our customer but here happening the bank clearing entry ie crediting bank account. I have tried to get the configuration where these accounts is configured and why its automatically posting to Bank account. Because we haven't given these accounts any where