Basically, you do number codes and people solve them, and say what they wrote and reply 
Here are numbers:
A1
B2
C3
D4
E5
F6
G7
H8
I9
J10
K11
L12
M13
N14
O15
P16
Q17
R18
S19
T20
U21
V22
W23
X24
Y25
Z26
Now go forth and make a code! c: I'll go first tho, figure it out :3
8,9 20,8,5,18,5

Here are numbers:
A1
B2
C3
D4
E5
F6
G7
H8
I9
J10
K11
L12
M13
N14
O15
P16
Q17
R18
S19
T20
U21
V22
W23
X24
Y25
Z26
Now go forth and make a code! c: I'll go first tho, figure it out :3
8,9 20,8,5,18,5