Specialist form of taxation that man supports (5)
I believe the answer is:
niche
'specialist form' is the definition.
'niche' can be an answer for 'form' (niche is a kind of form). I am unsure of the 'specialist' bit.
'taxation that man supports' is the wordplay.
I cannot really see how this works, but
'man' could be 'che' and 'che' is present in the answer.
This may be the basis of clue (or it may be nonsense).
'of' acts as a link.
Can you help me to learn more?
(Other definitions for niche that I've seen before include "Suitable slot" , "market area for specialists" , "Recess - alcove" , "somewhere comfortable" , "Select place in market" .)