Notes for class

• Watch after One URL, Seventy Requests, which draws the tree these messages build.
• The message format is RFC 9112 for HTTP/1.1. HTTP/2 (RFC 9113) and HTTP/3 carry the same three parts in binary frames.
• With X-Content-Type-Options: nosniff, a browser refuses a script that isn't labelled as JavaScript and a stylesheet that isn't labelled text/css, and stops guessing types elsewhere (MDN).
• registerProtocolHandler() needs HTTPS and works in Chrome and Firefox, not Safari. A custom scheme must start with web+ followed by lowercase letters, and the handler URL must be on the page's own origin (MDN).
• Try it yourself: open the Network panel in DevTools, click any request, and read its Headers tab for the first line and the headers, then its Response tab for the body.
• The narration is a synthetic voice (ElevenLabs). Timing follows the narration track, so a recorded voice-over can replace it cue for cue using the transcript.
• With Reduce Motion turned on in the operating system, the film keeps its fades and drops the sliding motion.
• Set in Atkinson Hyperlegible Next and Mono, typefaces the Braille Institute designed for readers with low vision.

Take it with you

• Video (MP4, 1080p, 6:57, 13 MB), with English captions built in
• Captions: WebVTT or SRT, for Canvas or YouTube
• Narration script (plain text) with chapter timecodes, for recording your own voice-over