For software that interfaces with Bitcoin Core via RPC, it can be useful to know whether the fRelayTxes flag is set. It could be added to `getnetworkinfo`.

if (block.vtx[i].IsCoinBase())
            return state.DoS(100, false, REJECT_INVALID, "bad-cb-multiple", false, "more than one coinbase");
    
    BOOST_FOREACH(const CTransaction& tx, block.vtx)
        if (!CheckTransaction(tx, state))
            return state.Invalid(false, state.GetRejectCode(), state.GetRejectReason(),
                                 strprintf("Transaction check failed (tx hash %s) %s", tx.GetHash().ToString(), state.GetDebugMessage()));
    unsigned int nSigOps = 0;
    BOOST_FOREACH(const CTransaction& tx, block.vtx)
    {
        nSigOps += GetLegacySigOpCount(tx);
    }
    if (nSigOps > MAX_BLOCK_SIGOPS)
        return state.DoS(100, false, REJECT_INVALID, "bad-blk-sigops", false, "out-of-bounds SigOpCount");
    if (fCheckPOW && fCheckMerkleRoot)
        block.fChecked = true;
    return true;
}
static bool CheckIndexAgainstCheckpoint(const CBlockIndex* pindexPrev, CValidationState& state, const CChainParams& chainparams, const uint256& hash)
{
    if (*pindexPrev->phashBlock == chainparams.GetConsensus().hashGenesisBlock)
        return true;
    int nHeight = pindexPrev->nHeight+1;
    
    CBlockIndex* pcheckpoint = Checkpoints::GetLastCheckpoint(chainparams.Checkpoints());
    if (pcheckpoint && nHeight < pcheckpoint->nHeight)
        return state.DoS(100, error("%s: forked chain older than last checkpoint (height %d)", __func__, nHeight));
    return true;
}
bool ContextualCheckBlockHeader(const CBlockHeader& block, CValidationState& state, CBlockIndex * const pindexPrev)