That is the same manual that shows up when I click on "help" in the program but thank you for posting the link!
I just found what I was looking for by going page by page on the entire thing.
I tell you what, this manual can be created a lot easier to find stuff.
Anyway, the 2 little icons that I was looking for were under:
[Organize video \ Rate and Tag video \ add comment markers and chapter markers]
and I must say, I'm glad I wanted to find out what they were because after reading how it works, it's a great feature adding comment markers!
@ Bengt Warleby,
Thank you as well for your reply.
You might like this Tutorial by Ken Stone. It is for iMovie 09, but there are only a few changes, and all the iMovie 09 stuff still works.
I will point you to the section on Markers, and you can find the rest from there.