Windows Explorer wasn’t responding well to a shared folder, so I was using cmd to quickly access what I wanted. Turns out I needed to change security settings on a folder to enable another domain user to access it. Then I realized I didn’t know how (in cmd). The network was local so I had no Internet access to help me.
Now that I have, I easily found the answer to be “cacls”. Looking at the syntax help I should be able to reproduce what I do with the GUI on the command line.