In previous version of OS X, I was able to edit the /Library/Preferences/com.apple.dockfixup.plist file to remove any persistent dock apps that I did not want in the dock for newly created users. Items like iBooks and Maps are not necessary for us.
In Yosemite, I no longer see the com.apple.dockfixup.plist file. It's replaced with a file called com.apple.dock.plist. When I look at that file, I see the following:
1 entry called: DesktopAdminImageGenerationNumber ( this is a Dictionary class)
It has another key called: GenerationNumger with a string of 2
Not sure what any of this means.
I also tried editing the default plist located in the dock application: System/Library/CoreServices/Contents/Resources/en.lproj/default.plist
Still no good. iBooks and Maps still show in the dock.
Any thoughts would be greatly appreciated.