What is the language "British"?

[Duncan Anderson]

On Monday, 28 August 2006 15:25, Timothy Murphy wrote:
> I was installing FC-5 yesterday,
> and I noticed that when asked to choose my language,
> I was given an extensive list which included "British" but not "English".
>
> I never heard this language described as "British" before.
<snip>

Presumably, they mean "British English" as opposed to "American English". What 
about other forms of "non-American" English?

cheers
Duncan