http://drupal.stackexchange.com/questions/4777/is-adding-indexes-to-a-drupal-database-safe

The code reported in that question, and in its answers is not automatically highlighted. As with the majority of the question on DA, the code should be automatically highlighted as PHP code; there are few exceptions where the code should be highlighted for a different programming language, but generally the code shown in questions (and answers) is PHP code.