The ipnareas table gives the areas of the localizations in the chronological.txt file.  Each entry in the latter table has two lines of information in the ipnareas table.  
The first line is a header, showing the date and time of the burst, and the elements that go into the localization.  For example, a triangulation consists of one or two RAs, 
Decs, Radii, and Uncertainties.  It may also have an ecliptic latitude band, planet-blocking, or other information.  The last three lines of the header are for the area of
the error box, expressed in steradians, square degrees, and the fraction of the sky covered by the box.  The second line in the table gives the numerical values of these
quantities.  The error box area is the area common to all the localizations.  For example, if a narrow IPN annulus intersects a large BATSE error circle, the area is that 
of the long, narrow error box which the two regions have in common.  If the IPN annulus (3 sigma) does not intersect the error box (one sigma),  no area is calculated, and the entry reads
"THERE IS NO INTERSECTION BETWEEN THE LOCALIZATIONS".  This can also occur, for example, if an IPN annulus does not intersect a Konus ecliptic latitude band (~90-95% confidence region). 

<p><a href="ipnareas">Table</a></p>