Of course contracts can be, and very many are,
concluded with conditions differing from those of the standard forms of contract
(GCA and ECC - See 04, Contracts), as long as these are well understood and are
clearly set out in unambiguous language, leaving no room for differing
interpretations. For example, one might agree to change the weight tolerance in
Article 2 of the ECC from 3% to 5%, in which case the contract should include a
paragraph to the effect that 'Article 2 of ECC is amended for this contract by
mutual agreement to read a tolerance of 5%'.
If a modification to an existing contract is agreed
then this should be confirmed in writing, preferably countersigned by both
parties. Adding the words 'without prejudice to the original terms and
conditions of the contract' ensures that the modification does not result in
unintended or unforeseen change to the original contract. A modification that is
not confirmed in writing could subsequently be repudiated or disputed by one of
the parties, for example during arbitration proceedings. Human memory is
fallible and there is nothing offensive in ensuring that all matters of record
are on record.