Re: telex messages could be legally binding
When I worked in the gas industry in the 1980s, all instructions were sent via telex for precisely that reason.
I worked in Central Control (Bryanston Street). We'd start a prediction run based on weather (also received via telex) then run over it for the most cost efficient way to deliver it based on a matrix of contracts and finally telex the gas rigs and head offices before 6pm to make it legal.
The main aim to buy gas as cheaply as possible and avoid using one of the RB-211 compressors which cost a lot of gas .....