Symbol ,Meaning
A,A
C,C
G,G
T,T
W,A or T
S,G or C
M,A or C
K ,G or T
R,G or A
Y,T or C
B,G or T or C
D,G or A or T
H,A or C or T
V,G or C or A
N,G or A or T or C
* https://www.pnas.org/content/83/1/4,