Why is it called nillable?

Question

In an XML schema you can mark an element as nillable meaning it can take an explicit NULL value. See nillable and minOccurs XSD element attributes for a great e

Answer 1

Nil has the same language roots as null. Nil comes from the Latin for nihil which means "nothing". "Null", while related, comes from the Latin for "none" (literally 'ne-' meaning "not" and 'ullus' meaning "anything"). While they are similar in meaning, they have some slightly nuanced differences.

In practical usage, 'null' is far more common stateside while 'nil' is more common in Europe. Most people tend to use them interchangeably in software development terms but in language usage 'nil' is more common, in my experience.