+.SS EXTENDED STORAGE FORMAT
+The previous section describes the conventional terminfo binary format.
+With some minor variations of the offsets (see PORTABILITY),
+the same binary format is used in all modern UNIX systems.
+Each system uses a predefined set of boolean, number or string capabilities.
+.PP
+The \fBncurses\fP libraries and applications support
+extended terminfo binary format,
+allowing users to define capabilities which are loaded at runtime.
+This
+extension is made possible by using the fact that the other implementations
+stop reading the terminfo data when they have reached the end of the size given
+in the header.
+\fBncurses\fP checks the size,
+and if it exceeds that due to the predefined data,
+continues to parse according to its own scheme.
+.PP
+First, it reads the extended header (5 short integers):
+.RS 5
+.TP 5
+(1)
+count of extended boolean capabilities
+.TP 5
+(2)
+count of extended numeric capabilities
+.TP 5
+(3)
+count of extended string capabilities
+.TP 5
+(4)
+count of the items in extended string table
+.TP 5
+(5)
+size of the extended string table in bytes
+.RE
+.PP
+The count- and size-values for the extended string table
+include the extended capability \fInames\fP as well as
+extended capability \fIvalues\fP.
+.PP
+Using the counts and sizes, \fBncurses\fP allocates arrays and reads data
+for the extended capabilities in the same order as the header information.
+.PP
+The extended string table contains values for string capabilities.
+After the end of these values, it contains the names for each of
+the extended capabilities in order, e.g., booleans, then numbers and
+finally strings.
+.PP
+Applications which manipulate terminal data can use the definitions
+described in \fBterm_variables\fP(3X) which associate the long capability
+names with members of a \fBTERMTYPE\fP structure.
+.
+.SS EXTENDED NUMBER FORMAT
+.PP
+On occasion, 16-bit signed integers are not large enough.
+With \fBncurses\fP 6.1, a new format was introduced by making a few changes
+to the legacy format:
+.bP
+a different magic number (octal 01036)
+.bP
+changing the type for the \fInumber\fP array from signed 16-bit integers
+to signed 32-bit integers.
+.PP
+To maintain compatibility, the library presents the same data structures
+to direct users of the \fBTERMTYPE\fP structure as in previous formats.
+However, that cannot provide callers with the extended numbers.
+The library uses a similar but hidden data structure \fBTERMTYPE2\fP
+to provide data for the terminfo functions.
+.SH PORTABILITY
+.SS setupterm