on:*

For events with capital letters, listener options, or if you need to attach event handlers directly to a DOM element instead of optimized delegating via the document, use on:* in place of on*.

<div on:DOMContentLoaded={(e) => console.log("Welcome!")} />

This directly attaches an event handler (via addEventListener) to the div.

An aditional special syntax that allows full control of capture, passive, once and signal is an intersection or combination of EventListenerObject & AddEventListenerOptions, as follows:

const handler = {
  handleEvent(e) {
    console.log(e)
  },
  once:true,
  passive:false,
  capture:true
}

<div on:wheel={handler} />

// or inline

<div on:click={{passive:true, handleEvent(e) { console.log("Weeeee!")}}} />

This new syntax replaces the now deprecated oncapture: and it's future proof for any posible new event listener options.