He's found in proper alphabetical order (5)
I believe the answer is:
ralph
'he's' is the definition.
'in proper alphabetical order' is the wordplay.
'in' says the answer is hidden in the clue.
'RALPH' is hidden within 'proper alphabetical order'.
'found' acts as a link.
(Other definitions for ralph that I've seen before include "--- Waldo Emerson, US writer" , "Boy's name" , "Piggy's friend (Lord of the Flies); --- Vaughan Williams" , "___ Fiennes, English actor, b. 1962" , "Fellow's name" .)