D-> whether there is a written contract
-> if they've put contract into written form, it then presumes everything the parties wanted is in the contract
-> if its signed, courts presume parties have read and agreed to its contents
routledge v mckay // L'estrange v graucob
-> if party is unaware of a term which is later used upon by one of the parties who knew of the time-> unlikely to be actionable
->depends on term and impact of its operation