-\tr{bar2/Wurble.iface} with the option
-\tr{-ohi bar2/Wurble.iface}\index{-ohi <file> option} (not recommended).
+\tr{bar2/Wurble.iface} with the option \tr{-ohi
+bar2/Wurble.iface}\index{-ohi <file> option} (not recommended).
+
+NOTE: Having the name of the interface file follow the module name
+and not the file name, means that working with tools such as
+\tr{make(1)} become harder. \tr{make} implicitly assumes that any
+output files produced by processing a translation unit will have file
+names that can be derived from the file name of the translation unit.
+For instance, pattern rules becomes unusable.