Has anyone else done anything like this?

Given my experiences with Dark Heresy I found that my copy quickly became very well thumbed and I started adding index tabs for the bits I wanted access to most often and most quickly.

With Rogue Trader I decided to tag the book ahead of time. Has anyone else tried this, and what exactly did they choose to tag?

(For me it was every career and most of the important tables on combat and starships)

Aye, I use torn off bits of post-it note on most of my well thumbed RPG books, it makes life very much easier

I want to ship you mine and pay you to do that for me!

I'm notorious for the amount of post-its sticking out of my RPG's - usually I have things like Skills, Talents, Start of the Combat section, Crit Tables, Creatures/NPC's, and so on - I also stick tabs in depending on if I want to reference a specific piece of the in book art during the game as I find it's a big help when trying to describe certain in-game events.

I'll usually mark chapters by using a marker on the edge of the pages. My WFRP1 Rulebook got that treatment....

I haven't done my RT nor DH books that way; instead, I copied the charts and tables I needed most and put them into a notebook in page protectors.

I'm with Aramis. I photocopy or print the pages I use often. Especially with DH I make sure to have all the relevant errata applied to the loose documents. Then I bunch them up, for example one printed erratad weapon and armor list, compiled with all the weapons from the end of IH, plus the melee weapons from several rulebooks (not the strange alien ones from CA and such), plus armors, plus weapon upgrades, plus ammo. All in all about 15 pages. Then I hand this document to my players when they are going shopping. Saves me a lot of bother. Similar with the career paths, damagetables, actions in combat etc etc, with the errata added in my nearly legible handwriting.

I've found that with such an extensive errata it is good to have rough copies of the rules that I can write on.