There are couple of questions that without the shell tag are incorrectly tagged and power users might get frustrated because of this:

• What are shells?
• Command history (previous and next command) in ngspice (migrated today, ngspice has an interactive shell mode)
• Change the color of the terminal (this asks how to change the terminal colors in the shell (most likely bash))

I'm sure there are more out there. I haven't found the exact reasons why shell and terminal where merged (the later happened even though the consensus was not to merge terminal).