The United States Department of Justice is wondering what part of “standard essential patents” tech companies don’t understand. Per Reuters, the DOJ and the U.S. Patent and Trademark Office this week put out a joint policy statement saying that companies should only be entitled to modest monetary compensation if others use their standard essential patents, and that they shouldn’t use those patents to seek outright sales bans of rivals’ products. The agencies’ reassertion of this principle is notable because Google (GOOG) last week agreed to stop using the standard essential patents acquired from Motorola in offensive patent lawsuits against competitors. Standard essential patents, for those who don’t know, cover key technologies that entire industries need to use in order to operate. Typically owners of these patents must agree to license them in a fair, reasonable and non-discriminatory fashion.