Why is null lowercase?

[bearophile]

Matthew Caron:

> Of all of the differences between C and D, the one which I have 
> the most difficulty adapting to is null being lowercase. Does 
> anyone know why this decision was made?

Probably because writing all in uppercase ugly. null is a keyword 
like the others, and they are in lowercase. DO YOU PREFER A 
LANGUAGE ALL IN UPPERCASE?

Bye,
bearophile