Various terms of art like "a new promise" and "a promise resolved with" are links to a W3C document like https://www.w3.org/2001/tag/doc/promises-guide/#a-new-promise or so. Since this text was written, however, that document has delegated its definitions to WebIDL. Affected links need to be changed to https://heycam.github.io/webidl/#a-promise-resolved-with and similar (against whatever is the canonical version of that URL, not sure if the heycam-specific URL is that).