Policy on Dorothy and Edward, and where to endorse it (6,4)
I believe the answer is:
dotted line
'where to endorse it' is the definition.
The definition suggests a singular noun which matches the answer.
'policy on dorothy and edward' is the wordplay.
'policy' becomes 'line' (I've seen this in another clue).
'on' says to put letters next to each other.
'dorothy' becomes 'dot' (nickname for someone called Dorothy).
'and' is a charade indicator (letters next to each other).
'edward' becomes 'ted'.
'dot'+'ted'='dotted'
'line' after 'dotted' is 'DOTTED LINE'.
'and' acts as a link.
Can you help me to learn more?
(Other definitions for dotted line that I've seen before include "sign on here" , "Site for signature" .)