It really does exist: BS 6008:1980, ISO 3103: Method for preparation of a liquor of tea for use in sensory tests. It's current, and active, five thousand words on how make a proper cup of tea. You can get it from the British Standards Institute for ï¿½22.
Found this on the Guardian website.
BS 6008: the abridged version
Use 2g of tea - plus or minus 2% - for every 100ml of water.
Tea flavour and appearance will be affected by the hardness of the water used.
Fill the pot to within 4-6mm of the brim with freshly boiling water.
After the lid has been placed on top, leave the pot to brew for precisely six minutes.
Add milk at a ratio of 1.75ml of milk for every 100ml of tea.
Lift the pot with the lid in place, then "pour tea through the infused leaves into the cup."
Pour in tea on top of milk to prevent scalding the milk. If you pour your milk in last, the best results are with a liquor temperature of 65-80C.
But they got it wrong, the tea goes in the cup first, THEN the milk. Everyone knows that.