I’ve experimented with a few different note-taking formulas in the past without much success. Often making the decoding all the more problematic as each method is overly convoluted. I like the idea of giving yourself room to add a summary of why you have taken those specific notes and to what end. How it all fits in with the bigger picture of your research.
I have been using symbols as a quick referencing tool as well. Asterix’ing key terms or phrases to look up after the seminar/class/lecture, arrows for key thoughts I would like to include in my blog or write about more generally, etc. This has helped me navigate through my notes when, at often times, I am bewildered by such an erratic display of information.