What should be used to represent lines in a matrix transcribed in the Nemeth Code, since the Nemeth codebook only mentions blank entries (not omission symbols) to be transcribed as short dashes (2022 Nemeth 25.8.1).
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.