+ X/Open Curses has more to say, but does not finish the story:
+
+ The inclusion of <curses.h> may make visible all symbols from the
+ headers <stdio.h>, <term.h>, <termios.h>, and <wchar.h>.
+
+ Here is a more complete story:
+
+ <STRONG>o</STRONG> Starting with BSD curses, all implementations have included
+ <stdio.h>.
+
+ BSD curses included <curses.h> and <unctrl.h> from an internal
+ header "curses.ext" ("ext" was a short name for <EM>externs</EM>).
+
+ BSD curses used <stdio.h> internally (for <STRONG>printw</STRONG> and <STRONG>scanw</STRONG>), but
+ nothing in <curses.h> itself relied upon <stdio.h>.
+
+ <STRONG>o</STRONG> SVr2 curses added <STRONG><A HREF="curs_initscr.3x.html">newterm(3x)</A></STRONG>, which relies upon <stdio.h>. That
+ is, the function prototype uses <STRONG>FILE</STRONG>.
+
+ SVr4 curses added <STRONG>putwin</STRONG> and <STRONG>getwin</STRONG>, which also use <stdio.h>.
+
+ X/Open Curses documents all three of these functions.
+
+ 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.
+
+ As a result, standard <curses.h> will always include <stdio.h>.
+
+ <STRONG>o</STRONG> X/Open Curses is inconsistent with respect to SVr4 regarding
+ <unctrl.h>.
+
+ As noted in <STRONG><A HREF="curs_util.3x.html">curs_util(3x)</A></STRONG>, ncurses includes <unctrl.h> from
+ <curses.h> (like SVr4).
+
+ <STRONG>o</STRONG> X/Open's comments about <term.h> and <termios.h> may refer to HP-UX
+ and AIX:
+
+ HP-UX curses includes <term.h> from <curses.h> to declare <STRONG>setupterm</STRONG>
+ in curses.h, but ncurses (and Solaris curses) do not.
+
+ AIX curses includes <term.h> and <termios.h>. Again, ncurses (and
+ Solaris curses) do not.
+
+ <STRONG>o</STRONG> X/Open says that <curses.h> <EM>may</EM> include <term.h>, but there is no
+ requirement that it do that.
+
+ 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>.
+
+ 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>.
+
+ <STRONG>o</STRONG> X/Open Curses says <EM>"may</EM> <EM>make</EM> <EM>visible"</EM> because including a header
+ file does not necessarily make all symbols in it visible (there are
+ ifdef's to consider).
+
+ For instance, in ncurses <wchar.h> <EM>may</EM> 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 <STRONG>_XOPEN_SOURCE</STRONG> feature
+ test macro.
+
+ <STRONG>o</STRONG> X/Open Curses documents one required header, in a special case:
+ <stdarg.h> before <curses.h> to prototype the <STRONG>vw_printw</STRONG> and
+ <STRONG>vw_scanw</STRONG> functions (as well as the obsolete the <STRONG>vwprintw</STRONG> and
+ <STRONG>vwscanw</STRONG> functions). Each of those uses a <STRONG>va_list</STRONG> parameter.
+
+ The two obsolete functions were introduced in SVr3. The other
+ functions were introduced in X/Open Curses. In between, SVr4
+ curses provided for the possibility that an application might
+ include either <varargs.h> or <stdarg.h>. Initially, that was done
+ by using <STRONG>void*</STRONG> for the <STRONG>va_list</STRONG> parameter. Later, a special type
+ (defined in <stdio.h>) was introduced, to allow for compiler type-
+ checking. That special type is always available, because <stdio.h>
+ is always included by <curses.h>.
+
+ None of the X/Open Curses implementations require an application to
+ include <stdarg.h> before <curses.h> because they either have
+ allowed for a special type, or (like ncurses) include <stdarg.h>
+ directly to provide a portable interface.
+
+
+</PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>