The battle of the forms describes the situation that results when parties involved in a commercial transaction exchange documentation with differing terms and conditions. In the event of a dispute between the parties, the courts have to decide what was agreed between the parties and, in the absence of a contract, the courts in some jurisdictions will seek the last unchallenged counter offer. In practice this often favours the supplier, as the quotation, order acknowledgement, proof of delivery and invoice all succeed buyer communications. See also Offer.