First and last of these in Porridge could be mentioned (6)
I believe the answer is:
quoted
'mentioned' is the definition.
The answer and definition can be both to do with communicating as well as being past participle verbs.
Maybe you can see a link between them that I can't see?
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for quoted that I've seen before include "Given citation" , "referred to" , "Cited (part of text)" , "Recited passage from poem or book" .)