Re: [xml-dev] Does it make sense to have a default with a nillable element?
says something about default values and xsi:nill
>
E has neither
element nor character [children], and
E is not
·nilled·...
in full it says
5 The appropriate case among the following is true:
5.1 If
D has a {value constraint}, and
E has neither
element nor character [children], and
E is not
·nilled· with respect to D
, then
all of the following are true:
5.1.1 If
E's
·governing type definition·
is
an ·instance-specified type definition·,
then
D.{value constraint}
is a valid default for the
·governing type definition·
as defined in Element Default Valid (Immediate) (§3.3.6.2).
5.1.2 The element information item with
D.{value constraint}.{lexical form}
used as its ·normalized value· is
locally ·valid· with respect to
the ·governing type definition· as defined
by Element Locally Valid (Type) (§3.3.4.4).
5.2 If D has no {value constraint}, or E has either element or
character [children], or E is
·nilled· with respect to D, then all of the following are true:
5.2.1 E is locally ·valid· with respect to the
·governing type definition· as defined
by Element Locally Valid (Type) (§3.3.4.4).
5.2.2 If D.{value constraint}.{variety} = fixed and
E
is not ·nilled· with respect to D, then
all of the following are true:
5.2.2.1 E has no element
information item [children].
5.2.2.2 The appropriate case among the following is true:
5.2.2.2.1 If E's ·governing type definition· is a Complex Type Definition
with {content type}.{variety} = mixed
, then the ·initial
value· of E
matches D.{value constraint}.{lexical form}.
5.2.2.2.2 If E's ·governing type definition·
is a Simple Type Definition
or a Complex Type Definition with
{content type}.{variety} = simple, then the ·actual value· of E is equal or identical to
D.{value constraint}.{value}.
so that's clear then.