There is a problem with this for news -- which may or
may not apply to mail -- in cases such as inadvertent
copyright violation. In such cases, it is of some legal
importance that cancel really and truly
*destroy* the original message;
hmmm, supose the posting and its cancelation were to end
up on an incrementaly built CDRom, would this imply the
need to mask the posting in some clever manner? an unlikely
capability, here the "obsoletes" concept seems more likely,
and so this issue raises legal headaches for those who might
want to redistribute news or whatever on CDRom. Looks like
someone needs to moderate that flow of "info" :-(.
--
dana s emery <de19(_at_)Umail(_dot_)umd(_dot_)edu>