Oh, to be a fly on the wall when a student made a formal request of a dress code. What could she ask for? What did the dress code say? And why am I talking about this? Because I read this on Yahoo! Style:
This is yet another case of an editor with a vocabulary deficit. She clearly has no idea what petition means and how to use it. As a verb petition means to ask for (by a petition) or to make a request. Maybe the student petitioned the school administration concerning the dress code. Maybe the student opposed the school dress code. Maybe the writer would learn some basic English.