Le 14/05/2016 18:14, Jonas Schnelli via bitcoin-dev a écrit :
> 
> AFAIK: Bip39 import (cross-wallet) is not supported by [...] Electrum [2] .
> 

That is correct. There are several reasons why I decided not to use
BIP39 in Electrum. One of them was that BIP39 seed phrases do not
include a version number. A version number is needed in order to
maintain backward compatibility, everytime you change the address
derivation.

Electrum will allocate a new version number for seed phrases that should
be derived to segwit addresses.

I guess BIP39 designers will have to change the semantics of their
checksum bits, in order to encode a version number for segwit.