Avoid canceling of events which do have multiple time-stamps

[Karl Voit <devnull@Karl-Voit.at>]

Hi!

Sometimes, I use single events and use
"org-clone-subtree-with-time-shift" to create clones for multiple
occurrences. (method A)

: ** <2014-08-30 Sat 15:00-17:00> Volleyball
:
: Do some sport.


For other events, I do have one single "* Volleyball" heading and
multiple time-stamps for each occurrence in its body. (method B)

: 
: ** Volleyball
: 
: - <2014-08-30 Sat 15:00-17:00> 
: - <2014-09-06 Sat 15:00-17:00> 
: - <2014-09-13 Sat 15:00-17:00> 


Unfortunately in the agenda view, both entries are visualized the same
way. This is causing issues in certain cases.

For example, when I see an event on my agenda and I know that I don't
have time for it, I usually cancel the event right away in my agenda.

However, when this time-stamp occured only in the body of a heading
(method B), cancelling does cancel *all* occurrences. For example when
I cancel "Volleyball" on the agenda of 2014-09-06, I'd cancel also
2014-08-30 (in the past) and 2014-09-13 (in the future).

And much worse: I do not notice my error.


There is a certain issue with this: how to determine whether or not a
time-stamp is the only one or if it is mentioned in the heading
itself.

Is there a clever way to differ the two methods so that we are able to
come up with different visualizations?

What are your thoughts on this issue?