> The problem is deciding where to put it in the event object.
> We shouldn't just jam any arbitrary things we want there.
>
> jQuery has event.data, which is set when the handler is bound. We could
do this for both types of highlights.

The data to channel is not yet available at the time when the handler is
bound. We could stuff our data there later, but I'm not sure that's
considered proper usage of the field.