CWG2732 Can importable headers react to preprocessor state from point of import?

Author: burblebee

source/modules.tex

@@ -448,6 +448,8 @@
 to the source file or header nominated by \tcode{H},
 which shall not contain a \grammarterm{module-declaration}.
 \begin{note}
+A header unit is a separate translation unit with
+an independent set of defined macros.
 All declarations within a header unit are implicitly
 exported\iref{module.interface},
 and are attached to the global module\iref{module.unit}.