Variant supplemental rules for vehicles.
From the cover
"Dark Heresy Apocrypha is an irregular series of articles and optional game rules for the Dark Heresy Roleplay Game. The Apocrypha contains all manner of exciting things such as rules additions, new types of character and different ways of constructing groups of Acolytes, as well as ideas for running particular types of game. Such knowledge however, comes with a warning—it is anticipated that some Apocrypha will have substantial implications for your games of Dark Heresy if you choose to use them. The Apocrypha are subject change and sit slightly outside of the purity of Dark Heresy’s core rules. For those of you who have steeled your soul and crave forbidden knowledge you read at you own risk! Enjoy"