"Kilt Casual" (?) at a Burns supper

[Spartan Tartan]

In this case, I certainly would NOT over think it. The very use of "pub style" tells me this is an "anything goes" event. I wouldn't be surprised to see flip flops and t-shirts. My guess is what you already mentioned, the organizers are hoping to drum up participation...

Although, I must agree too that "casual" just makes invitations confusing. I'd rather the invite say, "anything goes" or "wear whatever you want".


EDIT: I would add that since I do not have a jacket, I'd go with a shirt and tie and a sweater. I'd have my Flogging Molly T-shirt on underneath