"proper" dinner atttire

[Aces McGee]

Hey guys...really stupid question, I know, but I'm pretty much a dolt when it comes to stuff like this.

I'm going to dinner tonight at a somewhat nice Italian place in Georgetown (in DC). I forgot to wear a jacket to work (don't need to wear jackets or ties at my office), and I don't have time to go home before dinner.

Will I have a problem if I show up in a dress shirt, dress pants, and nice-ish shoes? The restaurant home page requests "proper attire" for dinner (lunch is casual), and I have no idea what that means. Why can't they just spell it out in plain English?

Here's the restaurant homepage, if that helps any.
Filomena

Thanks in advance.

-McGee