The assistant
Ask anything about Madeira
It searches every answer published on this site and gives you the one that fits, exactly as written, with its source attached.

Why it will sometimes tell you it does not know
This is a search over what is already here, not a chatbot that writes an answer for you. It can only return sentences that were published and sourced on this site, and it hands you the citation with each one.
That is a deliberate trade. A language model would answer more of your questions and phrase them more smoothly, and every so often it would state a tax rate that does not exist. On a site whose whole argument is that its numbers are real, that is not a quirk to be tuned down — it is the one failure that would make everything else here worthless.
So when nothing published here answers you, it says exactly that and points you at the guides or at a person. An assistant that admits a gap is more useful than one that fills it.