来龙去脉

láilóng-qùmài

[pedigree; origin and course of development; cause and effect; ins and outs; sequence of actions; ways and wherefores; whence and wither] 原是过去风水先生的说法, 认为山势如龙, 从头到尾都有血脉连贯。 现在常用来比喻事物的来历或事情的前因后果

文件的来龙去脉