Is your doc request related to a problem or existing docs? Please describe.
A developer reported that there's not an EIP165 requirement to go from L1 to L2, but there is to go from L2 to L1. Their Ethereum Mainnet token is a vanilla ERC20, but their implementation on OP Mainnet is not.
Describe the documentation you'd like
Clarify the ERC20 requirements to use the standard bridge.
Additional context
https://github.com/ethereum-optimism/developer-support/issues/141