It has to do with when you make a statement that  you try to use to cover all situations. Usually you can't  

這與你做出一個試圖用來涵蓋所有情況的聲明有關。通常情況下，你不能

make a blanket statement because there are always  exceptions. For example, all men are assholes.  

做一個全面的聲明，因為總是有例外。例如，所有男人都是混蛋。

Well, you can't say that because some men aren't. Blanket statement.

好吧，你不能這麼說，因為有些男人不是這樣。籠統的說法。