What is "an enclosed public space"?

From the newsgroup alt.fan.cecil-adams comes this Typo of the Week:
Charlie Pearce wrote:
> On Thu, 28 Jun 2007 03:04:48 -0400, "Jake Blues" <5htp@bellsouth.net>
> wrote:
>
>> Most of my friends in college smoked. Personally, I find smoking
>> very unattractive in women -- except when I've been drinking, in
>> which case I don't care. Haven't been in a bar in six years, though
>> presumably bars haven't changed much.
>
> PS Bras change in a big way in England and Wales from this Sunday, as
> all enclosed public spaces become non-smoking