-To use the pb_syshdr.h, define *PB_SYSTEM_HEADER* to be the name of your custom
-header file. It should provide all the dependencies listed above.
+To use the pb_syshdr.h, define *PB_SYSTEM_HEADER* as *"pb_syshdr.h"* (including the quotes).
+Similarly, you can provide a custom include file, which should provide all the dependencies
+listed above.