I think those came from Iliyan Peychevi's YUI Module explorer, that is probably where `yui-base` came from.  `event-key` is not used, the code just listens to the `keydown` event, no key event filtering except the one it does itself.  I don't believe in implicit dependencies, each module should state what it needs and if it is already there, the loader would take care of that. Even if this list wasn't created with YME, I would (or should) have added `base-base`.