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`.

nRecvBytes = 0;
    nTimeConnected = GetTime();
    nTimeOffset = 0;
    addr = addrIn;
    addrName = addrNameIn == "" ? addr.ToStringIPPort() : addrNameIn;
    nVersion = 0;
    strSubVer = "";
    fWhitelisted = false;
    fOneShot = false;
    fClient = false; 
    fInbound = fInboundIn;
    fNetworkNode = false;
    fSuccessfullyConnected = false;
    fDisconnect = false;
    nRefCount = 0;
    nSendSize = 0;
    nSendOffset = 0;
    hashContinue = uint256();
    nStartingHeight = -1;
    filterInventoryKnown.reset();
    fSendMempool = false;
    fGetAddr = false;
    nNextLocalAddrSend = 0;
    nNextAddrSend = 0;
    nNextInvSend = 0;
    fRelayTxes = false;
    fSentAddr = false;
    pfilter = new CBloomFilter();
    nPingNonceSent = 0;
    nPingUsecStart = 0;