From: John C Klensin [john-ietf(_at_)jck(_dot_)com]
Is bold must more or less compelling that underlined must. And
where does uppercase MUST fit in?
I fear the slightly richer publication format will give rise
to a slightly more complex revision of RFC 2119.
Let's try to remember that many of the comments/ requests for
alternate publication formats have been to make "display" more a
function of the devices being used. Depending on type style
variations (style, size, font variations, underlining, etc.)
would pretty much defeat that particular claimed requirement.
As I take Sam's note to sort of point out, even the use of
uppercase to imply specific semantics can be problematic; we
should at least strive to not make things worse, IMO.
I'm looking forward to the normative use of <BLINK>...</BLINK>.