Hi folks, I am really new to diigo and I already like it a lot!

I wonder if I could do a more sophisticated thing with diigo. Let me explain:

I have various pages with mixed contend, e.g. Articles on "Fruits". Now I'd like to highlight and tag everything concerning "Apples" and view it inside My Diigo. Another time I'd like to tag information on "Oranges" and keeping it separated from my "Apples" story .

As I understand it tags are URL-related whereas sticky notes are highlights-related. I'd like to know if there is a possibility to get highlights-related tags.