On Tue, May 29, 2018 at 5:13 AM, Jonas Schnelli via bitcoin-dev <
bitcoin-dev@lists.linuxfoundation.org> wrote:

> Hi
>
> If 520 bits are present, first 256 bits are the BIP32 chain code, to
> second 264
> bits (33 bytes) define the public key (according to BIP32)
>

In a 33 byte compressed public key, only 1 bit from the first byte conveys
information.  The other 7 bits can be discarded.  This will allow you to
reduce the bech32 encoded result by one character.