Notehand or speed-writing is a  shorthand for taking class and textook notes quickly. Although there are formal methods you can learn, many students adapt a portion of these formal methods for their own use. 

Symbols--Often borrowed from math, science, and business

             &      and   
             =      is
             >      greater than
             @      at
             #      number
             c.      about
             w/      with
             <      less than
             4      four, for,

Omitted Letters--especially one or two syllable words with short vowels
             nt       not
             ltr       letter
             dzn     dozen
             b/c      because
             whn     when

Changed letters--reflects phonetic sounds
             enf        enough
             thru       through
             r            are
             u           you

Specialized symbols--represent standard prefixes, suffixes, and word endings
     ment suffix--use a dash after the base word
          judg--   judgment
          pay--  payment
     ing ending--underline last letter of base word
          sing  singing
          writ     writing