Derives ten mats from public notices (14)
I believe the answer is:
advertisements
'public notices' is the definition.
The answer and definition can be both related to communication as well as being plural nouns.
Maybe you can see a link between them that I can't see?
'derives ten mats' is the wordplay.
'derives ten mats' anagrams to 'ADVERTISEMENTS'.
Though, I am unsure how this is indicated.
'from' is the link.
Can you help me to learn more?
(Another definition for advertisements that I've seen is " publicity".)