onInit and running code on initialisation

As with typical javascript you would not override an existing one by adding a new one. Much like setTimeout etc they all usually return an id pointing to the callback itself. This is also the way jQuery works (whether or not you like it; it's the way most people know callbacks especially in the global sense.

$(function(){ somethingToDoAtDOMLoad();}

$(function() { alsoExecuteAtDOMLoad(); }

EDIT: @Gordon I'm also in favor of E. I guess global.init is kind of old. 13.799 ± 0.021 billion years old in fact.