The library
What the letters mean
The letters after a Darjeeling, Assam or Ceylon tell you the size of the leaf and how many buds it holds. They say nothing about how it tastes.
SFTGFOP1
Special Finest Tippy Golden Flowery Orange Pekoe, first grade
Whole leaf, slow to give its flavour and the better for it. Golden tips: plenty of the unopened buds, which taste sweeter and softer. The 1 marks the best of that grade from the batch.
In the trade, TGFOP is said to stand for "Too Good For Ordinary People".
The "orange" has nothing to do with the fruit; it probably honours the Dutch House of Orange-Nassau, whose merchants first brought tea to Europe in quantity.