Crative, the one time I would make sure to say it's a British recipe is if the units of liquid measure are ounces, cups, pints, quarts, or gallons. Those only sound the same. Heck, US quarts have 36 US oz and Imperial quarts have 40 Imperial oz.
I always wonder when I read a Canadian recipe. Is it an older one in Imperial measure or is it a newer one in US measure?
Here in Canada some booze is still sold in "40 ouncers", even though the bottle says 1.14 litres.
May you live as long as you wish and love as long as you live.
Robert A. Heinlein