a: auth algo
b:
c: cipher
d: device name
e:
f: input file
g: unix group
h: print help text
i: local interface
j:
k: kd prf
l: ld_kdr
m: mux
n: ifconfig 
o: remote port
p: local port
q:
r: remote host
s: sender id
t: device type
u: unix username
v:
w: window size
x: post up script
y:
z:

A: master salt
B:
C: chroot directory
D: do not daemonize
E: passphrase
F:
G:
H: 
I: local sync interface
J:
K: master key
L:
M: remote sync hosts
N: 
O:
P: write pid file
Q:
R: route
S: local sync port
T:
U:
V:
W:
X: control host
Y:
Z: