I recently downloaded EN for the purposes of organizing a large academic research project and am evaluating whether to adopt it as my main strategy for organizing source materials. Question: I have some lengthy pdf files. I plan to annotate these (specifically, by tagging with keywords and/or making comments in the margins), but need my annotations to be searchable. Can I do this? Would this be done through Skitch? Again, it's not enough to tag the pdf as a whole; I need to be able to search annotations sprinkled throughout the pdf. Finally, not sure if this is relevant: I'm not currently a Premium member but am definitely willing to become one if I go with EN. I imagine this is a very basic question, but I can't seem to find an answer! Thank you.