+The Single Unix Specification, Version 2 states that
+\fBvw_printw\fR is preferred to \fBvwprintw\fR since the latter requires
+including \fB<varargs.h>\fR, which
+cannot be used in the same file as \fB<stdarg.h>\fR.
+This implementation uses \fB<stdarg.h>\fR for both, because that header
+is included in \fB<curses.h\fR>.