XML schema - backward compatible 1

[bond001]

Hello everyone,
How should I re-design XML schema in this scenerio?
Lets say my intial version (1.0) has element
<Sickness>Cold</sickness>
My new vesrion needs adding a sequence of properties like
<sickness>
<type>Contagious</type>
cold
</sickness>

1) Should I care about backward compatibility when I re-desin my schema?

2) Should I change schema and say "cold" as another new element?

My new schema looks like folowing
<complextype name="sicktype" mixed="true">
<sequence>
<element name="type" type="string/>
</sequence>
</complextype>

Is the above OK?

Thanks in advance

 

[tsuji]

1) It's a legitimate concern on your part.
2) No need (as well reflected in your new schema)

[3] Just add a minOccurs="0" to make it backward compatible.
[tt]
<complextype name="sicktype" mixed="true">
<sequence>
<element name="type" type="string[red]"[/red] [blue]minOccurs="0"[/blue] />
</sequence>
</complextype>
[/tt]

 

[tsuji]

Amendment

[3'] Forgotten to correct another original typo.
[tt]
<complex[red]T[/red]ype name="sicktype" mixed="true">
<sequence>
<element name="type" type="string" minOccurs="0" />
</sequence>
</complex[red]T[/red]ype>
[/tt]