[Design] Determining that collections behave like categories

[Jeffrey Harris]

Hi Folks,

I think that some users (myself included) don't instantly grasp that the
multiple calendars in iCal support copying of events.  While collections
turns out to do all the things categories do and more, when I see the
sidebar, I think of IMAP folders.  It would be nice if the
one-item-many-collections reality was somehow emphasized out of the box.

Sincerely,
Jeffrey