I had the same question... The first example code block is followed by the text: > I hope it’s obvious that the main difference is that “semantic indentation”

I had the same question... The first example code block is followed by the text: > I hope it’s obvious that the main difference is that “semantic indentation” differentiates between macros with body forms and regular function/macro invocations. But in the example code block the two "macros" examples were formatted identically in 'fixed' and 'semantic' styles. The only one that was different is "function call spanning two lines". So the stated point is far from obvious.