The S2 (Class II) plates are used on little school busses. This series started at S2-100A and went up to S2-999F.
1977	1978	1979 This one has a special sticker with a "SCHOOL VEHICLE" legend.
c.1980	The blue base started at S2-100G. This series flipped to 100A-S2 and progressed to 999M-S2 by 1993.
1981	1988	1989
1996	1996/1997	1996 Drew Steitz
With the 1993 base, School Vehicle plates became 7-digit. The new series started at 1000AS2.
1995	1996	1997
1998	1998   1999
After the 7-character plates went away, they went back to the 6-digit style. 6-digit plates re-started at 100N-S2. (Info from Dave Mackey)
1999	2000	2001
2002 A nice sequential group from Jeff Fazekas		2003
2004	2004 Approaching the end of the series...	2004 ON 1979 BASE
2005 On an older plate, with a passenger sticker.	In October 2004, 999Z-S2 was reached, and the series flipped to S2-A100.	2005
The changeover to the Avery base happened at S2-B100.
2005	2006	2007
2008