The most common and most likely answer to this crossword clue is the 4 plus 4 letter word CALL SIGN
I've seen this crossword clue in Independent
C
A
L
L
S
I
G
N
More clues leading to the result CALL SIGN
- Clubs justify storing case of labels for identification of station
- It’s heard on radio: ‘In California, 50 N American soldiers rising‘
- Transmission from broadcaster — in panic all’s ignored
- One identifies transmitter by name – Leo, perhaps
- Travel ID
- ID needed to subscribe after visit?
- It's heard on radio: 'In California, 50 N American soldiers rising'
- Mysteriously collapsing after killing op, what a pilot responds to
- Air Force One for example key in visits
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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.