Something is wrong
The page says one thing; the source says another.
Report what is wrong Subject: Wrong information · Page · What it says · What the source says · Where (link)Something is missing
A route, a question, a country, a case.
Say what is missing Subject: Missing · What · Where you looked for itAnything else
What helped, what confused you, what you would want next — a note of any length.
Write a note Subject: Feedback
The button opens Gmail. If Gmail is not yours, the second link opens your mail app; if that opens nothing, tap the address to copy it. A person reads every mail. Something wrong, confirmed against its source, is changed and the change gets a history line with the date. No reply is promised; a fix is the reply.
If you have a GitHub account
The tracker is where changes are recorded in public and where contributors work. The same things can go there instead:
Report a wrong value Suggest a route or a change