I did wonder that when looking at the link but P38 electrics aren't my game!
Bit more digging suggests that that is what it's being used for - thread titled 'Interior lamp delay relay': "Hi all, I've been given a Rover part number of a relay I need to use for something else,trouble is the local Rover dealer says its obselete and out of stock.The part number is YWC 10072.
I dont even know what model or year of cars it was fitted to,but finding one would be a big help in fixing a Range Rover diesel hot start problem - dont ask !
Thanks in advance for any help." https://www.mg-rover.org/threads/interior-lamp-delay-relay.202300/