Vitalik Buterin, the co-founder of Ethereum, said in a post that some block auctions can be used to limit the power of builders to deal with the risk of centralization, and mainly introduced two possible ways: Inclusion lists and Proposer Suffixes: In Inclusion Lists mode (Inclusion Lists), proposers provide an inclusion list, the list of transactions they require must be included in the block, unless the builder can completely fill the block with other transactions. This design is fairly simple, but weaknesses include: incentive compatibility issues; additional burden on proposers; builders can still engage in some abuse; partial enshrining is required for account abstraction to work. Another way to build this is to allow proposers to create a suffix for blocks. The builder sees no information about the proposer's intent when building the block, and the proposer is able to add any transactions the builder missed to the end. Doing so reduces incentive compatibility issues, and while it may be an additional burden on the proposer, between getting a response from the builder and having to publish the block, the proposer will get some MEV opportunities.