It's not the real deal, but https://www.quantumdata.com/assets/essentials_displayport_usb-c_dp_alt_mode_protocols_webinar.pdf https://www.quantumdata.com/assets

It's not the real deal, but https://www.quantumdata.com/assets/essentials_displayport_usb-c_dp_alt_mode_protocols_webinar.pdf https://www.quantumdata.com/assets/essentials_displayport_us... looks to be quite useful for understanding DP Alt Mode. I've used their DP regular protocol PDFs, though because this is a transcript of an animated webinar, there are images covering text which you'll need to remove in a PDF editor or LibreOffice Draw (which can import PDFs).