I have an idea that subject.

There are already BIP 21.

But Multisig request URI is non exist.

My idea is below:

bitcoin-sigreq://{{rawtx}}?{{param}}

rawtx: raw transaction (encoded by base64)

param:

- pubkey={{public key for sign key pair}}

- hd_wallet_position={{path for HD wallet position}}

This URI scheme is used for multisig request from website to user's local wallet.

How do you think ?