| CC | Description |
| C | This item has critical features such as tolerance, fit restrictions or application. Nuclear hardness properties have not been determined (not valid for input) |
| E | This item is a Flight Safety Critical Aircraft Part (FSCAP) and is specially designed to be or selected as being nuclear hard |
| F | This item is a Flight Safety Critical Aircraft Part (FSCAP) |
| H | This item is specifically designed to be or selected as being nuclear hard (ie. it will continue to perform its designed function in an environment created by a nuclear explosion). This item does not have any other critical features |
| M | This item is specifically designed to be or selected as being nuclear hard. In addition, this item has other critical features such as tolerance, fit restrictions or application |
| N | This item does not have a critical feature such as tolerance, fit restrictions or application. Nuclear hardness properties have not been determined (not valid for input) |
| X | This item does not have a nuclear hardened feature or any other critical feature such as tolerance, fit restriction or application |
| Y | This item does not have a nuclear hardened feature but does have other critical feature(s) such as tolerance, fit restriction or application |
