activeRef in amendments

for an amendment document, i am a bit confused by the <activeRef> and <original> elements in the <references> section -- 

My understanding is -- 
 
<original> has a reference to the amendment (the same as FRBRExpression/FRBRthis of the amendment  document)  ?

<activeRef > is this a reference to the Act/Bill being amended ? 

Is this correct ?