Just a quick one today, but earlier this week I read the Imperial Infantryman's Uplifting Primer: Damocles Gulf Edition which is a slim book from Games Workshop published "in universe". It purports to be a guide book given to each recruit in the Imperial Guard, which lists some of the basics for lasgun stripping, aliens (Orks: brittle boned cowards, much less muscular than they appear!) and the like. The book is rather dated now in terms of 40k background, but it was still fun to read, and I appreciated that I was able to get it from my local library, rather than spend the money needed to buy it on Amazon.
This edition of the book adds information about fighting the Tau, which was humorous enough, but it did have a couple of pictures of suitable interest that I copied them here.
The first picture shows the difference between a fine citizen of the Imperium, and a Tau sympathizer. There are not many pictures of Imperial citizens, so this was interesting. The second one shows the Tau "blood god" to which captives will be sacrificed. It occurred to me, that it would indeed be interesting to have Tau cultists, subverting the greater good for their ancient gods, but alas, current 40k has the space commies as being fairly "clean" aside from possible trickery with regard to the various subject/ally races.
Anyway, a fun little book if you can read it for free, but surely not worth $200 to buy it from Amazon.