Recommended changes to the DFDL language

[Roger L Costello]

Hi Folks,

I am converting 350 military data formats to DFDL.

Everyone of the 350 data formats has an optional choice:

<xs:choice minOccurs="0">

DFDL does not allow optional choice. Why?

I recommend changing the DFDL language to allow optional choice.

Everyone of the 350 data formats has branches of a choice that are optional:

<xs:choice>
    <xs:element name="foo" minOccurs="0">

DFDL does not allow branches in a choice to be optional. Why?

I recommend changing the DFDL language to allow optional branches of a choice.

Many of the 350 data formats have an element with complexType that is nillable 
and the nilValue is a hyphen.

DFDL does not allow an element with complexType to have a nilValue other than 
%ES;

I recommend changing the DFDL language to allow elements with complexType to 
have a nilValue other than %ES;

/Roger