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`.

pindex = miSelf->second;
            if (ppindex)
                *ppindex = pindex;
            if (pindex->nStatus & BLOCK_FAILED_MASK)
                return state.Invalid(error("%s: block %s is marked invalid", __func__, hash.ToString()), 0, "duplicate");
            return true;
        }
        if (!CheckBlockHeader(block, state))
            return error("%s: Consensus::CheckBlockHeader: %s, %s", __func__, hash.ToString(), FormatStateMessage(state));
        
        CBlockIndex* pindexPrev = NULL;
        BlockMap::iterator mi = mapBlockIndex.find(block.hashPrevBlock);
        if (mi == mapBlockIndex.end())
            return state.DoS(10, error("%s: prev block not found", __func__), 0, "bad-prevblk");
        pindexPrev = (*mi).second;
        if (pindexPrev->nStatus & BLOCK_FAILED_MASK)
            return state.DoS(100, error("%s: prev block invalid", __func__), REJECT_INVALID, "bad-prevblk");
        assert(pindexPrev);
        if (fCheckpointsEnabled && !CheckIndexAgainstCheckpoint(pindexPrev, state, chainparams, hash))
            return error("%s: CheckIndexAgainstCheckpoint(): %s", __func__, state.GetRejectReason().c_str());
        if (!ContextualCheckBlockHeader(block, state, pindexPrev))
            return error("%s: Consensus::ContextualCheckBlockHeader: %s, %s", __func__, hash.ToString(), FormatStateMessage(state));
    }
    if (pindex == NULL)
        pindex = AddToBlockIndex(block);
    if (ppindex)
        *ppindex = pindex;
    return true;
}
static bool AcceptBlock(const CBlock& block, CValidationState& state, const CChainParams& chainparams, CBlockIndex** ppindex, bool fRequested, CDiskBlockPos* dbp)