Options for smart but informal

[Nathan]

I agree. Also, what the heck is "semi-formal" and why do people keep using this term? To me, it makes no sense whatsoever.

Kyle is right. These words don't appear to be standard around the English speaking world. That having been said, here is the system in which I was raised. I don't use these terms for kilt attire as it seems they a) aren't universal and b) don't really apply. These appear on party invitations and office dress codes all over Canada, so they're worth knowing. Anyone else familiar with this nomenclature for orders of dress?

1) Come as you are - Anything goes so long as you're covered. Punk rock, hip hop and other street fashion welcome. Sometimes this comes with the caveat of "no colours or flags" meaning no gang symbols can be displayed.
2) Beach wear/swimming attire - again, self-explanatory.
3) Shirt and shoes required - pretty self explanatory. This is all that is required to be served at most restaurants in Canada. This typically precludes sandals.
4) Casual - Almost whatever you like including jeans, shorts, t-shirts, cords etc. Shirt may or may not have a collar and this is a most relaxed form of dress. Even when an event is "casual", there is often an expectation that clothing will be clean and that there will be no rude or offensive text or logos on shirts, no large holes in the jeans or nothing overly revealing. You can step it up to a sportscoat and still be casual but a tie, unless worn loose or ironically is probably overdressed.
5) Business casual on casual Fridays - chinos/khakis and a collared shirt. This includes short sleeve casual button down shirts (often prints with soft collars) and polo/golf shirts. In winter, a sweater/jumper can be worn over this but the collar and cotton trousers are the key to this mode. Again, the key here is no necktie.
6) Business casual - usually a sport coat and non-matching trousers with collared shirt. The tie is optional though usually avoided. The idea of business casual is that you will also fit in at the pub or on the golf course after work.
7) Club wear - This means a collared shirt, dress shoes and trousers/no jeans. Club clothing is often designed in shiny synthetic fabrics and closely tailored to distinguish it from office attire. Shirts are often designed to be worn untucked. Headwear is not permitted.
8) Semi-formal - Jacket and tie of any combination required. This includes sportscoats, blazers and business suits. It implies dress shoes either lace up or loafers.
9) Formal - Tuxedo. (I know, in the UK "formal" is white tie and a tuxedo is called a dinner jacket and is considered "semi-formal" when people use the term. We don't have monarchs and Lords and Ladies walking about here very often so white tie is so extremely rare here that the top level of dress for most people is a tuxedo. Often, dances are called "formals" especially in school and females wear ball gowns while males wear tuxedos. I could say "black tie" but that leads to some confusion since many people wear matching coloured bowties and waistcoats/cumberbunds and other wedding rental attire to formal to black tie funcitons. If you've got satin on your lapels and trousers and a shirt with studs down the front, you're probably good to go. Black is always better. Most use the term "black tie" and "formal" interchangably.

Here's what you almost never see/hear in my neck of the woods:

1) Morning Dress - I've only seen it worn in association with a Royal visit. People typically get married in suits or tuxedos even before 6pm. Traditionalists scoff but someone who wears a suit to work might feel the need to "step it up" for their wedding and the wedding rental industry doesn't push morning wear; they push tuxedos.
2) White Tie - almost never happens, again it would be a Royal visit. It does exist but is simply called "white tie".
3) Country/hunting/stalking wear - In the UK this can mean nice tweed. Here country wear is the same as Western wear and means a Stetson and jeans. This mostly applies to people attending the Calgary Stampede. Hunting wear is camo or orange and you buy it at Canadian Tire.

There is one other level of dress colloquially referred to as the "Canadian Tuxedo". This includes either:
a) A thick wool or flannel plaid "work shirt" usually in a red tartan like Rob Roy MacGregor and jeans or;
b) A blue denim jacket worn with blue denim jeans.