how to make open departement or open plu??

I have a client who is running a supermarket.

and they have many items which dont have a barcode on it.

so I need to make an open no tax plu and open tax plu or departements.

how can I make them??

I know that I can make an empty plu and change the price but

they dont want this way. they want to charge the no barcode item like cash register.

put the price and press a departent then it charged.

thank you.