File name extensions used and their meaning.

file name    explanation
extension 
---------    -----------------------------------------------------------
<none>       Default for documentation in standard format (implied .DOC) 
.BAS         File is program in Quick-Basic (MS-DOS). 
.DAT         Data file, fixed record length. Records are terminated by
             the sequence <CR><LF>. The record length listed in the 
             File Summary of the ReadMe file lists the records length 
             not including the record terminator bytes. The actual number 
             of bytes between the start of one record to the next is thus 
             recl (from the ReadMe/File Summary) + 2.
.DOC         Ascii text file with documentation.
.EXE         Executable binary file 
.F           Fortran program file
.FOR         Fortran program file
.HTM         File in hypertext markup language (HTML) format
.HQX         A Macintosh BINHEX file
.IDX         An index file (ASCII text)
.FIT         A FITS file. FITS files have a logical record format of 2880
             characters with no record terminators embedded. 
.LIS         A printer listing with printer symbols embedded.
.STY         A LaTeX style file.
.TAR         A unix TAR container binary file.
.TEX         A TeX or LaTeX file.
.TXT         An ASCII text file.
.ZIP         A file compressed using PKZIP.