cannot find the main account when i post the job card journal

I'm using the Dynamics AX 2012 demo system, when i post the job card journal for the production order. i found that two main accounts were used, but unfortunately i cannot find where they are configured.

The account 999999 is the main account that was configured in the "General Ledger" as the "Error Account". but i have no idea what is main account 600520 used for , the description for this main account is "Fixed overhead applied".

i have check the "item group", "cost categories", "resource", "resource group", but i still cannot find the main account "600520". 

any idea ?

many thanks.