Why is this an issue?

Shared naming conventions allow teams to collaborate effectively. This rule raises an issue when a local variable or function parameter name does not match the provided regular expression.

Noncompliant code example

With the default regular expression ^[a-z_][a-zA-Z0-9_]*$:

public function doSomething($myParam){
  $LOCAL;
  ...
}

public function do_something_else($my_param){
  $LOCAL;
  ...
}

Compliant solution

public function doSomething($myParam){
  $local;
  ...
}

public function do_something_else($my_param){
  $local;
  ...
}