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

If memory serves, it's called "nillable" because (some of) the SQL people in the room became concerned about possible confusion between the relevant concept in XSD and the relevant concept in SQL. They threatened to lie down in the road to stop the proposal unless the name was changed. So the WG changed the name.

(On the orthographic question, I think nilable would invite pronunciation with a long 'i'; I believe that both American and British English regularly double final single consonants following a short stressed vowel. Cf. 'tag', 'tagging', 'tagged', 'taggable'.)