Why stock symbols are not standard across brokers like zerodha icici etc?


I am trying to use bhavcopy to do some analysis.
But, stock symbols not being same across NSE, zerodha, icici direct etc is frustrating.
Why are stock symbols different?
We should push for a standard.
Can zerodha make the mapping csv accessible to us?


Stock symbols are standard as per my knowledge.

Can you elaborate your doubt with example ?