The most common and most likely answer to this crossword clue is the 10 letter word RED-PENCIL
I've seen this crossword clue in The Guardian
R
E
D
-
P
E
N
C
I
L
More clues leading to the result RED-PENCIL
Buddy explains!
The straight part
We know that "Correct/Correct" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case correct/correct = red-pencil.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.