When I use the same seed phrase for both Ethereum and RSK, why is my address capitalised differently?

Question

If I import the same private key in ETH and RSK networks, the account is the same but the capitalization is different. Why is this? Is this OK?

Answer 1

Capitalization is used as a checksum, and the following standards are involved

• SLIP-0044
• EIP-155
• EIP-1191

Some wallet software allow you to configure the chain ID/ network ID, and others do not

• In wallets that leave out the chain ID, the capitalization based checksum will be the same in RSK as that of Ethereum. Example: MetaMask
• In wallets that include the chain ID, the capitalization based checksum will be different in RSK compared to Ethereum. Example: Nifty Wallet.

In both cases, a workaround is possible, and specified in EIP-155: Use all lower case to skip checksum checks