As far as the pause symbol goes, many have noted it resembles an the notation for an open connection on an electrical schematic. Some say it is simply a stop symbol with a chunk carved out of its center.  至於暫停符號,許多人都注意到它類似於電路符號,有些人說這只是一個將中間挖掉一槓的停止符號。

We’d put our money on a more classical origin: In musical notation, the caesura indicates a-wait for it-pause. 


via The Secret Histories of Those @#$%ing Computer Symbols