What the GI means
Oolong carries more protected names than any other category, and Wuyi rock tea is the strongest of them.
The protected name is Wuyi yancha（武夷岩茶）, and it covers a production area rather than a style.
Anxi Tieguanyin is the second, and it is held by a local association rather than by one company.
Fenghuang dancong and Dongding are protected too, each with its own boundary document.
A buyer should know that a geographic name in China can be protected 3 different ways.
The first is product protection, administered by the national intellectual property office since 2018.
The second is a certification mark, registered as a trademark and enforced by whoever owns it.
The third is the agricultural product register, which is the weakest of the three and rarely used for tea.
So a packet may carry one mark, two marks or none and still hold leaf from the right hills.
Outside China almost none of these names is protected, and a Taiwanese style tea can be sold as anything.
The words on a packet are a legal claim inside China and a marketing claim nearly everywhere else.
What it guarantees
A geographic indication guarantees exactly 2 things, and it is fair to hold it to those two.
The first is that the leaf grew inside the boundary that the registration document draws.
For Wuyi that means the administrative area around the park, not the famous cliffs on their own.
The park itself sits at about 650 m, and the protected area is far larger than the scenic core.
The second guarantee is that the processing followed the method written into the standard.
Roasting is part of that method, so a green style Wuyi tea sits outside the description.
The Anxi method describes the pellet, and a loose leaf Tieguanyin fails it on the page.
Both guarantees are checkable, which is what makes them worth anything at all.
The boundary is a published list of townships, and a seller should be able to name one.
The method is a written sequence of steps, and the cup either matches it or it does not.
The 2021 agreement with the European Union lists 100 Chinese products in its first batch, and a few teas are on it.
What it does not
The thing a geographic indication does not guarantee is quality, and that is the gap that costs money.
A protected name covers the weakest tea made inside the boundary exactly as much as the best.
It does not guarantee the sub designation, which is where most of the value actually sits.
Zheng yan（正岩）in Wuyi is a smaller area inside the protected one, and the GI says nothing about it.
A seller can be honest about the protected area and dishonest about the cliff at the same time.
Cultivar is not fixed either, and roasting hides cultivar better than any other step does.
Freshness sits outside it too, and roasted tea is often sold 18 months after it was fired.
Harvest is not fixed, since the standard accepts leaf from 2 or 3 pickings.
Blending before firing is allowed, and leaf from outside the boundary is the usual addition.
Enforcement runs on complaints, so it usually happens after the sale rather than before it.
Treat the mark as a floor under the claim, never as a recommendation to buy.
How to use it
Use the protected name as the first filter and never as the last one.
Look for the mark and a licence number, since a printed mark with no number is decoration.
Ask which township the leaf came from, and note whether the answer comes quickly or drifts.
Brew a protected tea against an unprotected one from the same seller, same water and same leaf ratio.
That comparison costs a few grams and settles whether the name is worth paying for.
Ignore the GI completely when buying a daily drinker, since you are paying for paperwork.
Insist on it when the price is high, because there is otherwise nothing to anchor the claim.
For Wuyi, learn roast levels before you learn boundaries, since roast dominates the cup.
For Anxi, learn the difference between the green style and the traditional one before the district.
A protected name does not replace tasting, and anyone who says otherwise is selling something.
Buy the name when you can check it, and buy the cup when you cannot.