I never saw a Bitcoin Address Start with ww, so I asked in the signature campaign thread.
It is not an address on the bitcoin network, but rather an address on the Whirlwind platform.
What if someone sends their Bitcoin to this address without replacing the ww with a 1?
They should be sending coins via the Whirlwind website (not via a bitcoin wallet) to the address which starts with "ww".
I know some wallets will give a warning that it's an incorrect Bitcoin address, just like my Electrum wallet did, but my question is still the same how is an average Joe supposed to know that this is a Legacy address and he has to send his Bitcoin to 12xmfzikTonuQc3iw7Xezvd9qwHibxryRj and not to ww2xmfzikTonuQc3iw7Xezvd9qwHibxryRj.
Sending coins to 12xmfzikTonuQc3iw7Xezvd9qwHibxryRj via a standard bitcoin transaction will not have them show up on Whirlwind. This is just a standard bitcoin transaction. You could access these coins by importing your Whirlwind private key in to a normal wallet, but this transaction has nothing to do with Whirlwind.
If someone wants to send coins to ww2xmfzikTonuQc3iw7Xezvd9qwHibxryRj, then they do so via the pay to note feature on Whirlwind. These coins will only show up on Whirlwind and will not show up on the bitcoin network.