Chri5, officially, what you are suggesting is frowned on by C & G. In any case, if you have been taught correctly, you need no additional tabs to navigate around the book. Also, the index ought to be where you look as a last resort - best place to start is always page 3.
Funny then that absolutely every one of the 20+ candidates, a mixture of 1 day 17th update and 4 day 17th newbie 17th had tabs on the book.
Simple dividing of the book in to the Parts, and sub sections of 4 and 5, and the same with the appendix 1-15.
In honestly when all the NIC trainers encouraged us to do it, I find your "frowning" daft
As you know the courses are 2382-10 which I did, 60 Q's in 120 minutes or the 2381-20 which is the update for people with 16th and is 30 Q's in 60 minutes.
Pass rate is 65% and the primary requirement is to be able to read a book. If you can do that then that's 50% of the Q's passed.
The rest is down to being able to analyse the question correctly and find the answers in the BS7681:2008 red book. The OSG isn't in print, so that's out and I didn't know about the books mentioned further up the thread.
You can talk all you wish about methodology and how you 'should' read a guide / book, but ultimately it's different strokes for different folks and there were a few questions that answers HAVE to be cross referenced from the index.
The index is a smart move, because it will give more than one place to look. Important when a subject has requirements that need to be considered with other elements of the book.
Well that what I think anyway.
Just to add controversy I think 2381-10 and 2381-20 could be passed by anyone who can read.
There were at most 5 calculations and maybe only 30% of the questions required electrician 'savvy'.