Inline attributes and canCopy

Hi TC, we’ve run into a dilemma and require some expert guidance. The XLIFF 2.0 spec says this about Id:

·        
When used in

<segment>,

<ignorable>,

<mrk>,

<sm>,

<pc>,

<sc>,

<ec>, or

<ph> elements:

o   
The inline elements enclosed by a

<target> element MUST use the duplicate
id values of their corresponding inline elements enclosed within the sibling

<source> element if and only if those corresponding elements exist.

o   
Except for the above exception, the value MUST be unique among all of the above within the enclosing

<unit> element.

So, when an inline element is copied, I might get this example from the spec:

 

<unit id="1">

<segment>

  <source>Äter <pc id="1">katter möss</pc>?</source>

  <target>Do <pc id="1">cats</pc> eat <pc id="2" copyOf="1">mice</pc>?

  </target>

</segment>

</unit>

 

In order for this to meet the above constraint, the intended meaning is probably something like:

 

·        
inline elements enclosed by a 
<target> element MUST use the duplicate
id values of their corresponding inline elements enclosed within the sibling

<source> element if and only if those corresponding elements exist. *Copies of inline elements are not considered to be corresponding to the original elements enclosed within
 the sibling 
<source> element and do not need to have the same id.*

 

And if that is true, when we validate the constraint to make sure the *original* source and target inline element ids match, how do we know which one is the original one if copyOf is not required and they can be reordered?
 If I just rely on making sure at least one of the Ids match regardless of position, what happens if I deleted the original elements in <target> and add back in two new ones? Do I have to make sure at least one of the elements has an id that matches? It seems
 like a lot of processing just satisfy the constraint.

 

What is the logical reason for this constraint?

 

Thanks,

Ryan