+X/Open Curses has more to say,
+but does not finish the story:
+.RS 4
+.PP
+The inclusion of <curses.h> may make visible all symbols
+from the headers <stdio.h>, <term.h>, <termios.h>, and <wchar.h>.
+.RE
+.PP
+Here is a more complete story:
+.bP
+Starting with BSD curses, all implementations have included <stdio.h>.
+.IP
+BSD curses included <curses.h> and <unctrl.h> from an internal header
+"curses.ext" ("ext" was a short name for \fIexterns\fP).
+.IP
+BSD curses used <stdio.h> internally (for \fBprintw\fP and \fBscanw\fP),
+but nothing in <curses.h> itself relied upon <stdio.h>.
+.bP
+SVr2 curses added \fBnewterm\fP(3X), which relies upon <stdio.h>.
+That is, the function prototype uses \fBFILE\fP.
+.IP
+SVr4 curses added \fBputwin\fP and \fBgetwin\fP, which also use <stdio.h>.
+.IP
+X/Open Curses documents all three of these functions.
+.IP
+SVr4 curses and X/Open Curses do not require the developer to
+include <stdio.h> before including <curses.h>.
+Both document curses showing <curses.h> as the only required header.
+.IP
+As a result, standard <curses.h> will always include <stdio.h>.
+.bP
+X/Open Curses is inconsistent with respect to SVr4 regarding <unctrl.h>.
+.IP
+As noted in \fBcurs_util\fP(3X), ncurses includes <unctrl.h> from
+<curses.h> (like SVr4).
+.bP
+X/Open's comments about <term.h> and <termios.h> may refer to HP-UX and AIX:
+.IP
+HP-UX curses includes <term.h> from <curses.h>
+to declare \fBsetupterm\fP in curses.h,
+but ncurses (and Solaris curses) do not.
+.IP
+AIX curses includes <term.h> and <termios.h>.
+Again, ncurses (and Solaris curses) do not.
+.bP
+X/Open says that <curses.h> \fImay\fP include <term.h>,
+but there is no requirement that it do that.
+.IP
+Some programs use functions declared in both <curses.h> and <term.h>,
+and must include both headers in the same module.
+Very old versions of AIX curses required including <curses.h>
+before including <term.h>.
+.IP
+Because ncurses header files include the headers needed to
+define datatypes used in the headers,
+ncurses header files can be included in any order.
+But for portability, you should include <curses.h> before <term.h>.
+.bP
+X/Open Curses says \fI"may make visible"\fP
+because including a header file does not necessarily make all symbols
+in it visible (there are ifdef's to consider).
+.IP
+For instance, in ncurses <wchar.h> \fImay\fP be included if
+the proper symbol is defined, and if ncurses is configured for
+wide-character support.
+If the header is included, its symbols may be made visible.
+That depends on the value used for \fB_XOPEN_SOURCE\fP
+feature test macro.
+.SH NOTES
+.PP