multiple shortdesc in an abstract in a topic

In DITA 1.1, it appears that you can have more than 
one shortdesc in an abstract in a topic. 

If there are multiple shortdescs in an abstract, 
what do you do with them all?  Use the first? 
Combine them somehow?  If you need to override a 
shortdesc in a topic with a shortdesc from a map 
(topicmeta), and there is more than one in the topic, 
which one do you replace? Or do you replace them all?

paul