Adding a free text box into a List value within a CA

On top of being able to pre-set a series of values in a list in a CA, it would also be nice to enable a user to input a unique value in the CA list via the SFI. For example, if a job was to be completed outside of the standard accepted jobs (e), thee.g. a pre-releasn the user of the SFI may need to add an unique value to the pre-defined CA List to retrieve items from the crib, and so it can be shown on the report why the components were vended. Would also like to ensure the free text box can accept values from a barcode/QR code