Where is the best local place to store software repository?
 

I have 13 dvd set debian 8.5. I store it in /mnt.
I point /etc/apt/sources.list to it.
This works, but is there a more standard or official way to do it?

the first step if you have a problem is NOT to start a new thread, but to search for documentation.
e.g. like this: https://duckduckgo.com/?q=debian+wiki+local+repository

https://debian-handbook.info/browse/...epository.html

I devoted 40 minutes to this in your other thread.

Thank you for the fourty minutes. It was well spent. I also spent a long time studying what you have said.
On this topic, I found several diffrent opinions. My reply is in the other thread.