SQL*Plus formats
The following formats are used by the SQL*Plus ACCEPT and COLUMN commands
Column FORMATS
Code eg  Description
-- ----  ------------------------------
An A20   Char, VARCHAR2 (VARCHAR), LONG
         where n is the desired display width.
9  9999  The number of digits entered=display width. 
         Does not display leading zeroes.
0  0999  Displays leading zeroes.
   9990  Display 0 as '0' instead of ' ' 
$ $9999  Prefix a dollar sign
B B9999  Display 0 as ' ' instead of '0' 
MI 9999MI    Display minus signs "-"
PR 9999PR    Display minus in <brackets>
comma 9,999  Include commas
period 99.99 Align the decimal point 
V 999V99     Multiply value by 10n, where n is the number of "9's"
EEEE 9.999EEEE Display in scientific notation
DATE DATE    Display value as a date (US)