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`.

ReadCompactSize(vRecv); 
        }
        LOCK(cs_main);
        if (nCount == 0) {
            
            return true;
        }
        CBlockIndex *pindexLast = NULL;
        BOOST_FOREACH(const CBlockHeader& header, headers) {
            CValidationState state;
            if (pindexLast != NULL && header.hashPrevBlock != pindexLast->GetBlockHash()) {
                Misbehaving(pfrom->GetId(), 20);
                return error("non-continuous headers sequence");
            }
            if (!AcceptBlockHeader(header, state, chainparams, &pindexLast)) {
                int nDoS;
                if (state.IsInvalid(nDoS)) {
                    if (nDoS > 0)
                        Misbehaving(pfrom->GetId(), nDoS);
                    return error("invalid header received");
                }
            }
        }
        if (pindexLast)
            UpdateBlockAvailability(pfrom->GetId(), pindexLast->GetBlockHash());
        if (nCount == MAX_HEADERS_RESULTS && pindexLast) {
            
            
            
            LogPrint("net", "more getheaders (%d) to end to peer=%d (startheight:%d)\n", pindexLast->nHeight, pfrom->id, pfrom->nStartingHeight);