Or they could give their season ticket to a trusted member of the family to use?
There is no need to inform the club or request a scheme to do this. There are probably thousands at each game who are using someone else's season ticket. A mate of mine who has a season ticket at Atsenal has people sitting near him, and who have been for years, who don't actually know ther person who pays the club for the season ticket, owing to private arrangements even more outrageous than the occasional bit of lending to a family member or trusted friend.
Issues arise when kid tickets are used by adults, or when someone lends their ticket to a nob who gets chucked out, in which case chickens come home to roost,
I may of course have all this completely wrong.
I think LI was implying that an elderly vulnerable fan with a concession ST could pass this on to a younger, less vulnerable, member of the family who would normally be paying a higher rate!
Whilst a gesture, not sure why the younger beneficiary shouldn't have to pay the difference between the concession ST price and the relevant ST price!