In SSIS 2012, what is the purpose of flagging a package as an "Entry Point" package In the Visual Studio designer you can right click on a SSIS package and designate it as an "Entry Point" package"



Doing a search I found this page on MSDN which states:


  The value of 1 signifies that the package is meant to be started
  directly. The value of 0 signifies that the package is meant to be
  started by another package with the Execute Package task. The default
  value is 1.


With this flag enabled and disabled I have been able to execute a package directly.  

What is the purpose of enabling or disabling this flag?  Is it merely to document the intentions of your own SSIS packages or does SQL Server/SSIS behave differently when it enabled or disabled?
There's one behaviour I can think of:

Only packages with "Entry Point Package" set to 1 can be executed by catalog.create_execution

(see http://msdn.microsoft.com/en-us/library/ff878034.aspx)