(d) making the conclusion of contracts subject to acceptance by the other parties of supplementary obligations which, by their nature or according to commercial usage, have no connection with the subject of such contracts.
(d) chun conarthaí a thabhairt i gcrich, é a chur de choinnioll go nglacfaidh na páirtithe eile le hoibleagáidí forliontacha nach bhfuil baint ar bith acu, óna nádúr ná ó ghnás na tráchtála, le hábhar na gconarthai sin.