One who’s drafted isn’t taking against longhand (6)
I believe the answer is:
script
'longhand' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for script that I've seen before include "Written version of a play" , "Screenplay" , "Performance text" , "Person preparing text for film actors" , "Orginal document" .)