1  XTENSION 
2  BITPIX 
3  NAXIS 
4  NAXIS1 
5  NAXIS2 
6  PCOUNT 
7  GCOUNT 
8  TFIELDS 
. . . 

(other keywords, which must include ...)  
TFORMn, n=1, 2, ..., k where k is the value of TFIELDS  
. . . 

last  END 
'BINTABLE'
.
n_{row} =  TFIELDS i=1  r_{i}b_{i} 
(8.2) 
TFORMn value  Description  8bit Bytes 
L  Logical  1 
X  Bit  * 
B  Unsigned byte  1 
I  16bit integer  2 
J  32bit integer  4 
A  Character  1 
E  Single precision floating point  4 
D  Double precision floating point  8 
C  Single precision complex  8 
M  Double precision complex  16 
P  Array Descriptor  8 
^{*} number of 8bit bytes needed to contain all bits