`$` is fine as a Lisp symbol, but there is a problem with compatibility with treesit, so we will rename them. * `php-$this` → `php-this` * `php-$this-sigil` → `php-this-sigil` refs https://github.com/emacs-php/php-ts-mode/pull/68