SERIES 10 - September 2012!
Rimmer wouldn't wear this shirt for fear of being written up for insubordination. Even with no superiors around.
Cat wouldn't wear it, because it's not stylish enough for his wardrobe.
Kryten wouldn't wear it, he doesn't normally wear clothes.
But Lister would wear it.
According to Ian Symes's Smeg List, there are 227 unique occurrences of some combination of smeg on the show, which gives us 4.37 s/e (smegs per episode).