on quote.com livecharts the naz 100 e-mini is NQ01U.. 01 is the year, H = march, M = june, U = september, and Z = december.
also, SP01U for S&P 500 futures,
ND01U for nasdaq 100 futures,
ES01U for S&P 500 e-mini. other vendors may use a format like SP01U\ or SPU01..