Security alert local relayed incorrectly (10)

I believe the answer is:

collateral

I'm a little stuck... Click here to teach me more about this clue!

'security' is the definition.
(collateral is a kind of security)

'alert local relayed incorrectly' is the wordplay.
'alert local' anagrams to 'COLLATERAL'.
But, I'm not clear how the anagram is indicated.

Can you help me to learn more?

(Other definitions for collateral that I've seen before include "Guarantee" , "Secondary; parallel" , "damage?" , "running side by side" , "Security for loan repayment; secondary" .)

Want a hint initially instead of a full solution? Install my app