Field help (PTHLINACC1) 

These fields indicate the purchase accounting accounts. The charts of accounts that can be accessed depend on the account core model associated to the company of the movement. If these fields are not entered the account will be automatically determined by the accounting code for the product as a function of the parameters for the PORD automatic journal.
SEEINFO The presence of this field depends on the entry transaction used.
These accounts are loaded by default according to the accounts present in the order line that originated the receipt line.