Hi Gala,
The consensus of the committee is as follows:
Print should be followed and a long dash used to represent the printed underscore. If space is an issue, then the alternative choice would be a general omission symbol with a TN. We do <i>not</i> recommend the use of the short dash as NC 25.8.3.d specifically reserves its use for blank entries (i.e., blank spaces) in print.
Thanks
Mike