Currently, the "Events" section has a number of structural problems:

* The exact steps of event dispatch is unclear; although there are a number of
  rules defined in section 7.6, but it's still unclear how the UAs can apply
  them in the procedural definitions in the DOM specification.
    * For instance, when should a UA run "event path calculation algorithm"?
      How should it apply the algorithm when it's about to dispatch an event
      <http://dom.spec.whatwg.org/#dispatching-events>, in what order?

* It's super unclear what part of the specification is an extension to the
  DOM spec (where the behavior of events is defined), and what is an extension
  to the HTML spec (where every event that can happen in the HTML land is
  defined). Currently the both are ad-hocly intermixed.
    * For example, the algorithms in section 7 and 7.1 are basically part of
      the DOM specification, but events listed in section 7.1 are from
      the HTML specification.

There are also not-so-critial issues:
* Two algorithms "event path calculation algorithm" and "modified event path
  calculation algorithm" are almost identical except for one step. These can
  be consolidated into one.
* Limitation for mutation event types is written in the first paragraph of
  section 7, but it's unclear what the UAs are expected to do on such events.
* Section 7.7 should serve as informational purposes only.

With that in mind, I think the whole section needs some love. Especially,
we probably should consider how to separate the section into two pieces,
extension to the DOM spec and extension to the HTML spec, and how to glue
these. Doing so will make the events behavior more well-defined, I guess.