  "mempoolminfee": 0.00000000

When the minrelaytxfee is > 0.

if (!request.params[2].isNull())
        fMempool = request.params[2].get_bool();
    Coin coin;
    if (fMempool) {
        LOCK(mempool.cs);
        CCoinsViewMemPool view(pcoinsTip, mempool);
        if (!view.GetCoin(out, coin) || mempool.isSpent(out)) {
            return NullUniValue;
        }
    } else {
        if (!pcoinsTip->GetCoin(out, coin)) {
            return NullUniValue;
        }
    }
    BlockMap::iterator it = mapBlockIndex.find(pcoinsTip->GetBestBlock());
    CBlockIndex *pindex = it->second;
    ret.push_back(Pair("bestblock", pindex->GetBlockHash().GetHex()));
    if (coin.nHeight == MEMPOOL_HEIGHT) {
        ret.push_back(Pair("confirmations", 0));
    } else {
        ret.push_back(Pair("confirmations", (int64_t)(pindex->nHeight - coin.nHeight + 1)));
    }
    ret.push_back(Pair("value", ValueFromAmount(coin.out.nValue)));
    UniValue o(UniValue::VOBJ);
    ScriptPubKeyToUniv(coin.out.scriptPubKey, o, true);
    ret.push_back(Pair("scriptPubKey", o));
    ret.push_back(Pair("coinbase", (bool)coin.fCoinBase));
    return ret;
}
UniValue verifychain(const JSONRPCRequest& request)