It is observed that the spec is not very crisp on the topic of how `error` events fire (in the absence of a `load` event) for both script elements and stylesheet elements -- specifically dynamically created elements. 

This ostensibly has led to the current state of such event support cross-browser -- which is very inconsistent/buggy. It is requested that clarification be made for both events for both element types, such that specific bugs can filed against each browser to bring them all into conformance.

Specifically, it seems like in the case of `load` and `error`, one of the two events should *always* fire for a script/stylesheet element. There should never be a case where an element falls in between and fires neither event.

Furthermore, we should be crisp/clear on what constitutes a successful "load" of such elements, so that the absence of `load` can predictably be fired as `error`.

I suggest:

* `load` should only fire if the element in question results in a 2xx or 3xx HTTP status code. `load` should fire even if the parsing/execution of the resource fails, but should always fire *after* that attempt, to maintain how existing script.onload works.

* `error` should fire in any other case, which would correspond to 4xx and 5xx HTTP error status codes.

* `error` is *not* to fire for parse/execution errors in either element type (script, stylesheet) -- it is purely for "failed to load" type errors.

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Discussion:

In various browsers, various HTTP status codes result in either the `error` event firing or not, and in some cases, neither a `load` nor a `error` fires. The behavior is even more confusing because it's not the same for scripts as it is for stylesheets.

There's even a case where a browser fires `error` in the event of a script error, which is confusingly incompatible with other browsers on the topic.