The field attribute character also indicates one of the following field types, which indicates allowable input:
| Field Type | Description | 
| Alphanumeric * | All characters are allowed. | 
| Alphabetic only | Uppercase and lowercase letters, comma, period, hyphen, blank, and Dup key are allowed. | 
| Numeric shift | Automatic shift for numerics is enabled. | 
| Numeric only * | Digits 0-9, comma, period, plus, minus, blank, and Dup key are allowed. | 
| Digits only | Digits 0-9 and Dup key are allowed. | 
| Magnetic stripe reader | Data can be entered only via a magnetic stripe reader. | 
| Signed numeric | Digits 0-9, plus, minus, and Dup key are allowed. | 
* These are the only valid field types for a 3270 session.