Thanks. Am I right in assuming that "unused" means that the segment wasn't flown and even in a completely wild scenario of me buying a ticket for tomorrow, checking in, boarding, going "ooops, don't want to", offloading myself, forgetting about it, remembering 364 days from now, asking for money back - BA would then still refund the fare?

(And no, I have no intention of doing it, I am just trying to understand the rules!)