Why is Ripple's base58 alphabet so weird?
I don't know about the rest of the string but I think the leading bytes are ordered that way to make the types of "addresses" be human reconizable.

From a quick look at the source I think the leading characters, rpshnaf map like so:


r = public Ripple address
p = node private
s = Ripple secret
h = ?
n = node public
a = address family generator or seed ?
f = address family generator or seed ?


Of these, wallet owners have seen the r* and s* "addresses" and those running ripple will be have seen the n* and p* ones.