FluidTYPO3\Vhs\ViewHelpers\Format\EliminateViewHelper::eliminateLetters PHP Method

    protected function eliminateLetters($content)
    {
        $caseSensitive = (bool) $this->arguments['caseSensitive'];
        if (true === $caseSensitive) {
            $content = preg_replace('#[a-z]#', '', $content);
        } else {
            $content = preg_replace('/[a-z]/i', '', $content);
        }
        return $content;
    }