[nitpick] The wording of how to handle an empty filter list doesn't match what happens in practice

[ArcaneNibble]

In the section on "To request the "usb" permission", step 6.3 says "Remove devices from enumerationResult if they do not match a device filter in options.filters."

My interpretation of this sentence is that a device does not match a device filter if the list of filters is empty. This means that an empty filter list wouldn't ever return anything. However, that interpretation would be… rather silly and useless (since you can just pass a filter that doesn't filter anything), so Chrome does the sensible thing of treating an empty list as accepting everything.

[reillyeon]

Yup, that is what the spec should say and the filtering logic in Web Serial gets it right.