Many people think that the word " tip " is an acronym for " to insure promptness . "

许多人都认为“tip”一词是“toinsurepromptness”的简称。

At that time , every local hotel had a special bowl on its tables , on which wrote " to insure promptness " .

那时，当地酒店的餐桌上一般都摆着写有“toinsurepromptness”（保证及时服务）的碗。