Note reciprocation about a point of principle (5)
I believe the answer is:
tenet
'principle' is the definition.
(a tenet is a principle or value)
'note reciprocation about a point' is the wordplay.
'note reciprocation' becomes 'tt' (I can't justify this - if you can you should give a lot more credence to this answer).
'about' is an insertion indicator.
'a point' becomes 'ENE' (ENE is an example).
'tt' enclosing 'ene' is 'TENET'.
'of' is the link.
Can you help me to learn more?
(Other definitions for tenet that I've seen before include "A palindromic doctrine or belief" , "A belief or creed - a palindrome" , "Article of belief" , "Belief held as true" , "Palindromic principle or belief" .)