@ (at sign) in Drupal strings

Question

In another question, someone posted this code in an answer to my question.

drupal_set_message(
  t(\'Some Message @title\'), array(\'@title\' => $form_state[\         


        

Answer 1

In Drupal, an @ sign in front of a placeholder is used to signal to Drupal's string parser to run the string attached to the placeholder through check_plain().

More info about string placeholders can be found on the t() API page.