Yes, Taped blank paper on front of book and wrote NEC #104, 105...etc.....Motors, Meters, Transformers, Per Unit, etc and after each subject put prob #.....
I also created an index for these types of books. Basically it references the category (ex.-transportation), the topic (horizontal curve), problem number and page number. Set this up in Excel and it can be taped inside the back cover of the book for quick reference.
I made this a while ago when i was a noob and didn't have a good grasp on a problems "category" if you will but might save yall some time (i.e. generator problem is really a fault, xmfr is really a pu, etc)
