The first is a communication of some sort (6)
I believe the answer is:
letter
'communication of some sort' is the definition.
'letter' can be an answer for 'communication' (letter is a kind of communication). I am not certain of the 'of some sort' bit.
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for letter that I've seen before include "Unit of alphabet" , "who may offer terms to residents?" , "he leases" , "Character - landlord - epistle" , "reference?" .)