This is just some initial text to get going; other contributions welcome.
I’d like to include other workflows, such as hardware wallets and (manual) coinjoins. However, the former will in practice require PSBT interfaces for existing hardware devices, and the second can really use some extra RPCs first.
104+
105+Later, when *V* BTC has been received on *Amulti*, and Bob and Carol want to
106+move the coins in their entirety to address *Asend*, with no change. Alice
107+does not need to be involved.
108+- One of them - let's assume Carol here - initiates the creation. She runs
109+ `walletcreatefundedpsbt [] {"Asend":V} 0 false {"subtractFeeFromOutputs":[0]}`,
"includeWatching":true is also necessary here since Amulti is only solvable by Bob, not spendable. By default watching only outputs will not be selected.
81+### Workflows
82+
83+#### Multisig with multiple Bitcoin Core instances
84+
85+Alice, Bob, and Carol want to create a 2-of-3 multisig address. They're all using
86+Bitcoin Core.
walletcreatefundedpsbt below may choose outputs that are not for Amulti
106+move the coins in their entirety to address *Asend*, with no change. Alice
107+does not need to be involved.
108+- One of them - let's assume Carol here - initiates the creation. She runs
109+ `walletcreatefundedpsbt [] {"Asend":V} 0 false {"subtractFeeFromOutputs":[0]}`,
110+ and gives the produced PSBT *P* to Bob. *P* contains Carol's signature but
111+ not Bob's.
walletcreatefundedpsbt does not sign. Carol needs to use walletprocesspsbt first.
85+Alice, Bob, and Carol want to create a 2-of-3 multisig address. They're all using
86+Bitcoin Core.
87+
88+Setup:
89+- All three call `getnewaddress` to create a new address; call these addresses
90+ *Aalice*, *Abob*, and *Acarol*.
bech32 as their address type as well as the multisig address type, or at least suggest that being consistent will reduce the chances of confusion?
getaddressinfo will provide for all address types. Maybe it is needed with addmultisigaddress, but I don’t think this is necessary.
getnewaddress calls it doesn’t matter, as they only communicate the pubkey anyway. For addmultisigaddress I’ve added a comment.
99+ addresstype option each, to avoid constructing different versions due to
100+ differences in configuration.
101+- They also run `importaddress "Amulti" "" false` to make their wallets treat
102+ payments to *Amulti* as contributing to the watch-only balance.
103+- Others can verify the produced address by running
104+ `createmultisig 2 ["Kalice","Kbob","Kcarol"]`, and expecting *Amulti* as
createmultisig and addmultisigaddress may use different address types, you probably will need to add a comment here that different address types may be needed in order to get the correct address.
109+
110+Later, when *V* BTC has been received on *Amulti*, and Bob and Carol want to
111+move the coins in their entirety to address *Asend*, with no change. Alice
112+does not need to be involved.
113+- One of them - let's assume Carol here - initiates the creation. She runs
114+ `walletcreatefundedpsbt [] {"Asend":V} 0 false {"subtractFeeFromOutputs":[0], "includeWatching":true}`.
[{"Asend":V}]
