In https://bugs.python.org/issue33053#msg313966, jwilk noted that it isn't obvious from https://docs.python.org/3/using/cmdline.html#cmdoption-m how to keep the current directory from being added to `sys.path` when using the -m switch. The answer is to pass the `-I` switch as well (to activate isolated mode), but there's no cross reference to help readers discover that fact.

https://docs.python.org/3/using/cmdline.html#id2 is the main documentation for isolated mode, so the steps needed to close this issue are:

1. At least add a reference from the -m switch documentation to the -I switch documentation
2. Review the other parts of the `using` docs that describe how `sys.path` is initialised, and reference the -I switch documentation where relevant