The `-n` flag will ignore warnings completely, while often it is useful to see them and to fix them.
Using `--runtime-set ignore_warnings_on_exit 1` in the Travis script instead, warnings will be shown, both when a developer runs PHPCS on their own machine, as well as in Travis, but warnings will not cause a failed Travis build.
The `-v` flag will list each file being scanned. This is intended for debugging purposes and not needed for normal use.
The link was pointing to the `WordPress-Core` ruleset, while `_s` uses the `WordPress` ruleset which encompasses more than just the core rules.
Pointing to the repo + the wiki seems more appropriate to me.
If the file is called `phpcs.xml` or `phpcs.xml.dist`, it is automatically picked up by PHPCS.
A `phpcs.xml` is given preference over a `phpcs.xml.dist` file. So renaming the file to `phpcs.xml.dist` allows for people to use the file provided by `_s` if they choose not to add their own, but also leaves people the freedom to easily overrule it.