Sales & Use Tax Private Letter Ruling - Enterprise Server Operating System Software Documents SUPLR 2010 0004 SUPLR 2010 0017 SUPLR 2010 0018 SUPLR 2011 0001 SUPLR 2012 0009 SUPLR 2012 0010 SUPLR 2012 0016 SUPLR 2012 0020 SUPLR 2012 0024 SUPLR 2013 0020