Recommendation paragraph mentions how the multi-tab, but not single-tab should behave. 

There's one problem in particular.
In a scenario where multi-tab and single-tab application are participating in the same session and these events are subsequently received:
1. Patient-1 -open
2. Patient-2 -open

It is important that while single-tab application closes Patient-1 and opens Patient-2, it must not send Patient-1 -close event. Otherwise, multi-tab application would receive the -close event and close Patient-1. Which means multi-tab does not work.    

Suggested additional bullet point in Recommendations paragraph: 
"Single-tab applications SHALL not send a -close event when a subsequent -open event is received"