By the Book——依照慣例

** very correctly（非常正確）// according to correct procedures（按照正確程序）// strictly according to the rules（嚴格按照規則）// formally, authoritatively or accurately（正式、權威地或準確地）// operate under regulations, law, contract, etc.（根據法規、法律、合同等操作）

~~ 按常規；按規則；依照慣例；按章辦事；規規矩矩來；墨守成規地辦一切事情

~~ go by the book // play by the book // play by the rules // abide by the rules // abide by the law // by the numbers // throw the book at someone 狠狠責罰某人

!! The "book" in this expression is a set of established rules or, originally, of moral (law) or religious (bible) precepts. The swearing on the Christian Bible in court is still common today.

（“書”在這種表述裏是一套已建立的規則，最初或是關於道德（法律）或宗教（聖經）的誡命。今天在法庭上對着基督教聖經而發誓仍然很普遍。）

>> This president does not act by the book.

（這位總統並非依照慣例來辦事。）

>> Regarding whether the No. 8 typhoon signal should be hoisted in Hong Kong, the Observatory will use the wind data of 8 designated wind measurement stations as reference. If 4 or more of the 8 of them meet or will reach the gale intensity (that is, the continuous wind reaches 63 to 117 kilometers per hour) index, the No. 8 typhoon signal will be hoisted by the book.

（對於香港是否應懸掛八號風球，天文台會以八個指定測風站的風力資料作參考。如果八個當中有四個或以上達到或預料達到烈風（即持續風力達每小時六十三至一百一十七公里）指標，便會按常規懸掛八號風球。）

學勤進修教育中心英語專科導師 李啟文 教授