Hi to all,

I copied an orgmode setup from http://www.newartisans.com/2007/08/using-org-mode-as-a-day-planner.html in order to test the described way of GTDing there. Since it works fine for me, I am trying to understand, what's going on beyond the surface. I found the expression above in the setup elisp file. After examining the manual and serveral sites, I still don't understand the term [?a] within that statement. Can anybody brighten my mind?

Thank you all!