Differences between Dbase III and Dbase IV

    Dbase IV adds field type "F" Float
    Dbase IV adds a more sophisticated DBT memo file, utilizes logic to reclaim disk space on memo field updates
    Dbase IV adds support for MDX multi tag indices
    
    
    
    
Version III Field Types

    C	Char
    N	Numeric
    D	Date
    M	Memo
    L	Logical
    
    
Version IV Field Types

    C	Char
    N	Numeric
    D	Date
    M	Memo
    L	Logical
    F	Float	(Similar to numeric)