Several bugs (e.g. Issue 15327 and Issue 15271) have been filed suggesting that people aren't really clear on how argparse handles argument name collisions or how they can get it to do what they want.

I think these problems could probably be solved by a "Name Collision" section (or something like that) in the argparse documentation. It would give a few example problems and show how to resolve them. Some things to include:

* What happens when two arguments have the same dest (Issue 15271), with solutions including action='append' or different dest= values combined with identical metavar= values.

* What happens when a parser and a sub-parser share some of the same argument names (Issue 15327), with solutions including specifying different dest= values for the parser and sub-parser

* A brief mention and cross-reference to the "conflict_handler" section.