eclipse - How do you find the locationURI of menu contributions? -

I have been able to add an item to the popup menu when right-clicking on the file in the project explorer Adding something like this:

  & lt; Extension point = "org.eclipse.ui.menus" & gt; & Lt; Menu all distribution popup = "wrong" location URI = "popup: org.eclipse.ui.navigator.ProjectExplorer #PopupMenu? After = additions" & gt; & Lt; Command command Id = "commands.mycmd" label = "do foo" style = "push"> & Lt; / Order & gt; & Lt; / MenuContribution & gt; & Lt; / Extension & gt;   
 Now, the only reason I knew to use  org.eclipse.ui.navigator.ProjectExplorer  because this is what everyone else does (There is no record of this in the eclipse PDF document). The problem is that I want the same functionality in navigator and package explorer views (right-click on the file and you can do this as "xup".  How do I get the locationURI of these two two views ( Package Explorer and Navigator)   
 I have tried to type  alt + shift + F2  to find such information, but eclipse does not allow you when you Activate mode , Then to get information on the tab.   
 
 
 Use  
  LocationURI = "popup: org.eclipse.ui.navigator.any?after = additions" & gt;   
 this will do the trick.