The properties scroll-timeline-name and view-timeline-name both have the grammar:

[ none | <dashed-ident> ]#

but state their computed value should be "the keyword none or a list of CSS identifiers".

What does that mean the computed value should be in cases like:

scroll-timeline-name: none, none;

or

scroll-timeline-name: --foo, none, --bar;

The text "the keyword none or a list of CSS identifiers" seems to imply either a single keyword none OR a list of identifiers, but when there is more than one use none, I'm not sure what should be used.