Exactly the same (5)
'exactly the same' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for identical that I've seen before include "Selfsame" , "Indistinguishable" , "Similar" , "as B and B" , "Like two peas in a pod" .)
(Other definitions for ditto that I've seen before include "Mark used to indicate repetition" , "Copy" , "couple of marks" , "Dot it for the same again" , "As per previous" .)