Pragmatic type on a register (7)
I believe the answer is:
realist
'pragmatic type' is the definition.
(I've seen this before)
'on a register' is the wordplay.
'on' becomes 're' ('on' can be mean 'with reference to').
'register' becomes 'list' (listing is a kind of registering).
're'+'a'+'list'='REALIST'
(Other definitions for realist that I've seen before include "Saltier (anag.)" , "One without illusions" , "Plato, for example" , "One has no fancy ideas" , "Someone who's pragmatic" .)