The most common and most likely answer to this crossword clue is the 6 letter word QUOTED
I've seen this crossword clue in The Guardian
Q
U
O
T
E
D
Buddy explains!

The straight part
We know that "Referred to" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case referred to = quoted.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.
What does QUOTED mean?
QUOTED verb- To repeat the exact words of (a person).
- To repeat (the exact words of a person).
- To prepare a summary of work to be done and set a price.
- (Commerce) To name the current price, notably of a financial security.
- To indicate verbally or by equivalent means the start of a quotation.
- To observe, to take account of.