- X/Open Curses states that the <EM>ACS</EM><STRONG>_</STRONG> definitions are <STRONG>char</STRONG> constants. For
- the wide-character implementation (see <STRONG>curs_add_wch</STRONG>), there are analo-
- gous <EM>WACS</EM><STRONG>_</STRONG> definitions which are <STRONG>cchar_t</STRONG> constants.
+ X/Open Curses states that the <STRONG>ACS_</STRONG> definitions are <STRONG>char</STRONG> constants. For
+ the wide-character implementation (see <STRONG>curs_add_wch</STRONG>), there are
+ analogous <STRONG>WACS_</STRONG> definitions which are <STRONG>cchar_t</STRONG> constants. Some
+ implementations are problematic:
+
+ <STRONG>o</STRONG> Some implementations define the ACS symbols to a constant (such as
+ Solaris), while others define those to entries in an array.
+
+ This implementation uses an array <STRONG>acs_map</STRONG>, as done in SVr4 curses.
+ NetBSD also uses an array, actually named <STRONG>_acs_char</STRONG>, with a <STRONG>#define</STRONG>
+ for compatibility.
+
+ <STRONG>o</STRONG> HPUX curses equates some of the <STRONG>ACS_</STRONG> symbols to the analogous <STRONG>WACS_</STRONG>
+ symbols as if the <STRONG>ACS_</STRONG> symbols were wide characters. The
+ misdefined symbols are the arrows and other symbols which are not
+ used for line-drawing.
+
+ <STRONG>o</STRONG> X/Open Curses (issues 2 through 7) has a typographical error for
+ the ACS_LANTERN symbol, equating its "VT100+ Character" to <STRONG>I</STRONG>
+ (capital I), while the header files for SVr4 curses and the various
+ implementations use <STRONG>i</STRONG> (lowercase).
+
+ None of the terminal descriptions on Unix platforms use uppercase-
+ I, except for Solaris (i.e., <STRONG>screen</STRONG>'s terminal description,
+ apparently based on the X/Open documentation around 1995). On the
+ other hand, the terminal description <EM>gs6300</EM> (AT&T PC6300 with EMOTS
+ Terminal Emulator) uses lowercase-i.