+These functions may be macros:
+.sp
+.RS
+\fBattroff\fR, \fBwattroff\fR, \fBattron\fR, \fBwattron\fR,
+\fBattrset\fR, \fBwattrset\fR, \fBstandend\fR and \fBstandout\fR.
+.RE
+.PP
+Color pair values can only be OR'd with attributes if the pair
+number is less than 256.
+The alternate functions such as \fBcolor_set\fP can pass a color pair
+value directly.
+However, ncurses ABI 4 and 5 simply OR this value within the alternate functions.
+You must use ncurses ABI 6 to support more than 256 color pairs.
+.SH EXTENSIONS
+.PP
+This implementation provides the \fBA_ITALIC\fP attribute for terminals
+which have the \fBenter_italics_mode\fP (\fBsitm\fP)
+and \fBexit_italics_mode\fP (\fBritm\fP) capabilities.
+Italics are not mentioned in X/Open Curses.
+Unlike the other video attributes, \fBA_ITALIC\fP is unrelated
+to the \fBset_attributes\fP capabilities.
+This implementation makes the assumption that
+\fBexit_attribute_mode\fP may also reset italics.
+.PP
+Each of the functions added by XSI Curses has a parameter \fIopts\fP,
+which X/Open Curses still (after more than twenty years) documents
+as reserved for future use, saying that it should be \fBNULL\fP.
+This implementation uses that parameter in ABI 6 for the functions which
+have a color-pair parameter to support \fIextended color pairs\fP:
+.bP
+For functions which modify the color, e.g.,
+\fBwattr_set\fP,
+if \fIopts\fP is set it is treated as a pointer to \fBint\fP,
+and used to set the color pair instead of the \fBshort\fP \fIpair\fP parameter.
+.bP
+For functions which retrieve the color, e.g.,
+\fBwattr_get\fP,
+if \fIopts\fP is set it is treated as a pointer to \fBint\fP,
+and used to retrieve the color pair as an \fBint\fP value,
+in addition
+retrieving it via the standard pointer to \fBshort\fP parameter.
+.PP
+The remaining functions which have \fIopts\fP,
+but do not manipulate color,
+e.g., \fBwattr_on\fP and \fBwattr_off\fP
+are not used by this implementation except to check that they are \fBNULL\fP.