This is a good intro. But I don't understand why the author says in the Searching section: "In the image below, the colon is missing but required." when in fact

This is a good intro. But I don't understand why the author says in the Searching section: "In the image below, the colon is missing but required." when in fact the picture is correct - you don't need the colon. It works the same either way, and omitting it is faster.