This vector shows what characters cause an external URL when used before an @
const anchor = document.createElement('a');anchor.href="https://psres.net"+String.fromCodePoint($[i])+"@example.com";0x0D
if(anchor.host !== 'example.com'){0x0D
log($[i])0x0D
}anchor.href="https://psres.net"+String.fromCodePoint(35)+"@example.com";0x0D
if(anchor.host !== 'example.com'){0x0D
alert(35)0x0D
}anchor.href="https://psres.net"+String.fromCodePoint(47)+"@example.com";0x0D
if(anchor.host !== 'example.com'){0x0D
alert(47)0x0D
}anchor.href="https://psres.net"+String.fromCodePoint(63)+"@example.com";0x0D
if(anchor.host !== 'example.com'){0x0D
alert(63)0x0D
}anchor.href="https://psres.net"+String.fromCodePoint(92)+"@example.com";0x0D
if(anchor.host !== 'example.com'){0x0D
alert(92)0x0D
}