Can someone explain the purposes of some new SSIS 2012 properties?

As someone who's learning SSIS, there are some new properties in SSIS 2012 that I can't find any documentation/explanations for. Thus, I'm hoping someone can explain them:

In the Maintenance Cleanup Task, the BIDS property grid has a DeleteFromAllBricks property. What does that property control?

In the Back Up Database Task, I see CopyOnlyBackup, IgnoreReplicaType, and UseExpiration (which is also present in 2008) properties. What are these properties for?

In one of my dtsx files, there's a Rebuild Index task with a SkipUnsupported property. What does SkipUnsupported do?

Note that none of these properties have their description fields set in BIDS and when searching online, I can't find any definitions. 

Thanks,

-Craig