The documentation is weak.
This would replace all of the -n with Dave.
You need to be careful because some letters might be reserved.
The flags add options.
i is used to ignore cases. Like Apple and apple
g is used to match every occurrence.
I noticed the 2nd image used Fred instead of Dave. It’s the same otherwise. -n is just an example. It could be anytime. It just needs to be unique enough to not cause accidental matches.