In the database structure editor, the graphical objects to the right of the field names are icons that represent which data type has been selected for the field. They can be changed to the letter indicating the field type or number indicating the maximum length of alpha fields.

To switch from icons to letters:

Select Database Properties from the File menu.
Click on the Design Environment tab (the 4th tab).
Uncheck the Use Icons for the Field Types check box.
Click OK.