freshman stripe
n.— «Also at UCD: the infamous Freshman Stripe…Since the inner campus is closed to automotive traffic, many, many people ride bikes to class. When the rains come in late Fall, the freshman can always be spotted because they have a vertical stripe running up their backs, caused by the spray from their tires. Eventually they wise up and buy fenders.» —“Re: Spotting Freshmen?” by Scott Fischbein Usenet: alt.folklore.college Sept. 27, 1993. (source: Double-Tongued Dictionary)