DS1 has an interview coming up for a course at University (not for a degree course, if you're wondering about the timing).
The invitation specifically says there's no dress code, wear what's comfortable. That would be scruffy, baggy hiking trousers and a heavy rock band t-shirt, which is basically is uniform outside of work. Even at work he wears the same trousers with their regulation polo shirt. He's never been one for following fashion or caring about his appearance, has always prioritised comfort.
What should he wear?