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 explanation.
What I'm curious about is why is it called
nillable? I always see nillable and think it's a typo!
I appreciate that
nil is a synonym for
null. What I'm wondering is why
nil was chosen, rather than the more common (in computer science)
null. Particularly as it should really be
nilable (note the single L)!