According to @adam3us, only a narrow subset of rules is consensus-enforceable in Bitcoin-like systems; minimum relay fee rates and minimum fee bumps for RBF make transaction relay anti-DoS. Source: Adam Back on X https://twitter.com/adam3us/status/1962089352739357036 Bitcoin Core implements these protections at the policy layer via minrelaytxfee and incrementalrelayfee defaults and BIP125, which requires replacements to pay at least the original total plus an incremental fee, increasing spam costs and stabilizing mempool relay under load. Source: Bitcoin Core bitcoind options -minrelaytxfee and -incrementalrelayfee https://bitcoincore.org/en/doc/26.0.0/man/bitcoind/ and BIP-0125 https://github.com/bitcoin/bips/blob/master/bip-0125.mediawiki For BTC traders, during fee spikes, low-fee or under-bumped RBF transactions can be rejected below the minimum relay feerate or evicted when mempools are full, extending on-chain settlement times; using competitive feerates or RBF fee-bumps (bumpfee RPC) raises inclusion probability. Source: Bitcoin Core mempool-limit policy https://github.com/bitcoin/bitcoin/blob/master/doc/policy/mempool-limit.md and Bitcoin Core bumpfee RPC https://bitcoincore.org/en/doc/26.0.0/rpc/wallet/bumpfee/