When the structure has been exported as XML, among other things, the XML contains the type of each field. In the structure XML, the type is specified as the "type" attribute within the element. Here is the list of these types and what each one denotes:

XML Type ID	4D Data type
1	Boolean
3	Integer
4	Long Integer
5	Integer 64 bits
6	Real
7	Float
8	Date
9	Time
10	Text
12	Picture
14	Text, with the Stored in record property checked
18	Blob