It would be nice if searching for the word "freestanding" in the standard would reach the predefined macro that lets users detect whether an implementation is freestanding. In n4849, the search would miss __STDC_HOSTED__ in [cpp.predefined].

I recommend editorially changing the text.

Edit cpp.predefined 1.5:

The integer literal 1 if the implementation is a hosted implementation or the integer literal 0 if it is not a freestanding implementation.