It would have been useful to know before spending two hours of my weekend proofreading a 96-page document that approximately 50% of my corrections would be rejected on the grounds that "we can't change their text" (surely if someone gives you copy for inclusion in your publication you can copy-edit it for typos, grammar, etc.?) and "it's house style".
House style (largely undocumented) includes: not using hyphens, ever, under any circumstances; italicising any instance of an "e-" prefix (e.g. e-learning, e-mail -- yes, hyphens are allowed there, because that's house style); and freely overriding any pre-declared (sorry, pre declared) aspect of house style because "we don't do it like that" and "it's house style".
Still, I've only been shouted at once so far today, for the unrelated error of failing to understand that "What's this software for? What does it do?" meant "Which of my email folders should I file the receipt in?"