Why is null lowercase?

[Don]

On Friday, 25 January 2013 at 01:17:44 UTC, Ali Çehreli wrote:
> On 01/24/2013 12:42 PM, Matthew Caron wrote:
>
> >> for not null checks
> >>
> >> if ( ptr !is null) ...
> >
> > And too much perl has me wanting to write:
> >
> > if (ptr is not null)
>
> IIRC, the !is operator is thanks to bearophile.

No, it's from 2002 (well, it was !==, renamed to !is in 2005).
Bearophile only joined us about the time D2 began, in late 2007.