In light of the University’s financial policies and in fairness to those who are properly enrolled, I remind you of the University’s policy prohibiting students from attending, being evaluated, auditing, or otherwise participating in courses without being officially enrolled. Instructors may not allow students to attend classes or submit work unless they appear on the official class list or are attending with instructor approval for the purpose of making up an Incomplete (I) grade in a prior term. Check your class roster regularly to ensure that everyone attending is registered for the class.
Read the full policy in the Academic Rules section of coursecatalog.syr.edu
CHANGES TO REGISTRATION
You may make changes to your registration after the semester begins, adding, or withdrawing from classes in accordance with published deadlines. While the student normally initiates registration and subsequent changes, the student’s school(s)/college(s) of enrollment may also initiate such actions. Instructors also have the option to administratively drop students who do not attend the first week of classes (up to and including the add deadline).
The Health Center or the Bursar’s Office may cancel your registration. No other University persons or units may make substantive changes to an undergraduate student’s schedule of classes without first securing the formal permission of your home school/college.
(See http://coursecatalog.syr.edu/content.php?catoid=3&navoid=270#Registration for the full text of the policy.)