In the prepare mass additions form, the invoice number field is editable, what is Oracles intention

In the prepare mass additions form, the invoice number field is editable, what is Oracles intention on this?When an user tries to capitalize an invoice, the first step is we  change the queue from New to post. Immediately the cursor will go to Invoice field. Here if the user by mistake if he does any changes in the invoice field manually  and saves the transaction by mistake, then the original invoice no details gets overtyped. So there will be a mismatch between AP invoice no we have received vs manual no the user has changed.  So I feel that the