diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index 55ab9dc23b..2f2b2d5c30 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -395,6 +395,73 @@ void CRegTestParams::UpdateVersionBitsParametersFromArgs(const ArgsManager& args
     }
 }
 
+/**
+ * Custom params for testing.
+ */
+class CCustomParams : public CRegTestParams {
+    void UpdateFromArgs(ArgsManager& args)
+    {
+        UpdateVersionBitsParametersFromArgs(args);
+
+        consensus.nSubsidyHalvingInterval = args.GetArg("-con_nsubsidyhalvinginterval", consensus.nSubsidyHalvingInterval);
+        consensus.BIP16Exception = uint256S(args.GetArg("-con_bip16exception", "0x0"));
+        consensus.BIP34Height = args.GetArg("-con_bip34height", consensus.BIP34Height);
+        consensus.BIP34Hash = uint256S(args.GetArg("-con_bip34hash", "0x0"));
+        consensus.BIP65Height = args.GetArg("-con_bip65height", consensus.BIP65Height);
+        consensus.BIP66Height = args.GetArg("-con_bip66height", consensus.BIP66Height);
+        consensus.powLimit = uint256S(args.GetArg("-con_powlimit", "7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"));
+        consensus.nPowTargetTimespan = args.GetArg("-con_npowtargettimespan", consensus.nPowTargetTimespan);
+        consensus.nPowTargetSpacing = args.GetArg("-con_npowtargetspacing", consensus.nPowTargetSpacing);
+        consensus.fPowAllowMinDifficultyBlocks = args.GetBoolArg("-con_fpowallowmindifficultyblocks", consensus.fPowAllowMinDifficultyBlocks);
+        consensus.fPowNoRetargeting = args.GetBoolArg("-con_fpownoretargeting", consensus.fPowNoRetargeting);
+        consensus.nRuleChangeActivationThreshold = (uint32_t)args.GetArg("-con_nrulechangeactivationthreshold", consensus.nRuleChangeActivationThreshold);
+        consensus.nMinerConfirmationWindow = (uint32_t)args.GetArg("-con_nminerconfirmationwindow", consensus.nMinerConfirmationWindow);
+
+        consensus.nMinimumChainWork = uint256S(args.GetArg("-con_nminimumchainwork", "0x0"));
+        consensus.defaultAssumeValid = uint256S(args.GetArg("-con_defaultassumevalid", "0x00"));
+
+        nPruneAfterHeight = (uint64_t)args.GetArg("-npruneafterheight", nPruneAfterHeight);
+        fDefaultConsistencyChecks = args.GetBoolArg("-fdefaultconsistencychecks", fDefaultConsistencyChecks);
+        fMineBlocksOnDemand = args.GetBoolArg("-fmineblocksondemand", fMineBlocksOnDemand);
+        m_fallback_fee_enabled = args.GetBoolArg("-fallback_fee_enabled", m_fallback_fee_enabled);
+
+        bech32_hrp = args.GetArg("-bech32_hrp", bech32_hrp);
+        base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1, args.GetArg("-pubkeyprefix", 111));
+        base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1, args.GetArg("-scriptprefix", 196));
+        base58Prefixes[SECRET_KEY] =     std::vector<unsigned char>(1, args.GetArg("-secretprefix", 239));
+
+        std::string extpubprefix = args.GetArg("-extpubkeyprefix", "043587CF");
+        assert(IsHex(extpubprefix) && extpubprefix.size() == 8 && "-extpubkeyprefix must be hex string of length 8");
+        base58Prefixes[EXT_PUBLIC_KEY] = ParseHex(extpubprefix);
+
+        std::string extprvprefix = args.GetArg("-extprvkeyprefix", "04358394");
+        assert(IsHex(extprvprefix) && extprvprefix.size() == 8 && "-extprvkeyprefix must be hex string of length 8");
+        base58Prefixes[EXT_SECRET_KEY] = ParseHex(extprvprefix);
+
+        const std::string magic_str = args.GetArg("-pchmessagestart", "FABFB5DA");
+        assert(IsHex(magic_str) && magic_str.size() == 8 && "-pchmessagestart must be hex string of length 8");
+        const std::vector<unsigned char> magic_byte = ParseHex(magic_str);
+        std::copy(begin(magic_byte), end(magic_byte), pchMessageStart);
+
+        vSeeds.clear();
+        if (gArgs.IsArgSet("-seednode")) {
+            const auto seednodes = gArgs.GetArgs("-seednode");
+            if (seednodes.size() != 1 || seednodes[0] != "0") {
+                vSeeds = seednodes;
+            }
+        }
+    }
+
+public:
+    CCustomParams(const std::string& chain, ArgsManager& args) : CRegTestParams(args)
+    {
+        strNetworkID = chain;
+        UpdateFromArgs(args);
+        genesis = CreateGenesisBlock(strNetworkID.c_str(), CScript(OP_TRUE), 1296688602, 2, 0x207fffff, 1, 50 * COIN);
+        consensus.hashGenesisBlock = genesis.GetHash();
+    }
+};
+
 static std::unique_ptr<const CChainParams> globalChainParams;
 
 const CChainParams &Params() {
@@ -404,13 +471,15 @@ const CChainParams &Params() {
 
 std::unique_ptr<const CChainParams> CreateChainParams(const std::string& chain)
 {
+    // Reserved names for non-custom chains
     if (chain == CBaseChainParams::MAIN)
         return std::unique_ptr<CChainParams>(new CMainParams());
     else if (chain == CBaseChainParams::TESTNET)
         return std::unique_ptr<CChainParams>(new CTestNetParams());
     else if (chain == CBaseChainParams::REGTEST)
         return std::unique_ptr<CChainParams>(new CRegTestParams(gArgs));
-    throw std::runtime_error(strprintf("%s: Unknown chain %s.", __func__, chain));
+
+    return std::unique_ptr<CChainParams>(new CCustomParams(chain, gArgs));
 }
 
 void SelectParams(const std::string& network)
diff --git a/src/chainparamsbase.cpp b/src/chainparamsbase.cpp
index 1e70a3739e..1a4b53a352 100644
--- a/src/chainparamsbase.cpp
+++ b/src/chainparamsbase.cpp
@@ -17,11 +17,12 @@ const std::string CBaseChainParams::REGTEST = "regtest";
 
 void SetupChainParamsBaseOptions()
 {
-    gArgs.AddArg("-chain=<chain>", "Use the chain <chain> (default: main). Allowed values: main, testnet, regtest", false, OptionsCategory::CHAINPARAMS);
+    gArgs.AddArg("-chain=<chain>", "Use the chain <chain> (default: main). Reserved values: main, test, regtest", false, OptionsCategory::CHAINPARAMS);
     gArgs.AddArg("-regtest", "Enter regression test mode, which uses a special chain in which blocks can be solved instantly. "
                                    "This is intended for regression testing tools and app development.", true, OptionsCategory::CHAINPARAMS);
     gArgs.AddArg("-testnet", "Use the test chain", false, OptionsCategory::CHAINPARAMS);
-    gArgs.AddArg("-vbparams=deployment:start:end", "Use given start/end times for specified version bits deployment (regtest-only)", true, OptionsCategory::CHAINPARAMS);
+    gArgs.AddArg("-vbparams=deployment:start:end", "Use given start/end times for specified version bits deployment (regtest or custom only)", true, OptionsCategory::CHAINPARAMS);
+    gArgs.AddArg("-seednode=<ip>", "Use specified node as seed node. This option can be specified multiple times to connect to multiple nodes. (custom only)", true, OptionsCategory::CHAINPARAMS);
 }
 
 static std::unique_ptr<CBaseChainParams> globalChainBaseParams;
@@ -40,8 +41,8 @@ std::unique_ptr<CBaseChainParams> CreateBaseChainParams(const std::string& chain
         return MakeUnique<CBaseChainParams>("testnet3", 18332);
     else if (chain == CBaseChainParams::REGTEST)
         return MakeUnique<CBaseChainParams>("regtest", 18443);
-    else
-        throw std::runtime_error(strprintf("%s: Unknown chain %s.", __func__, chain));
+
+    return MakeUnique<CBaseChainParams>(chain, 18553);
 }
 
 void SelectBaseParams(const std::string& chain)
diff --git a/src/init.cpp b/src/init.cpp
index 69b9213848..6a26010882 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -349,6 +349,7 @@ void SetupServerArgs()
     // Hidden Options
     std::vector<std::string> hidden_args = {"-rpcssl", "-benchmark", "-h", "-help", "-socks", "-tor", "-debugnet", "-whitelistalwaysrelay",
         "-prematurewitness", "-walletprematurewitness", "-promiscuousmempoolflags", "-blockminsize", "-dbcrashratio", "-forcecompactdb", "-usehd",
+        "-con_fpowallowmindifficultyblocks", "-con_fpownoretargeting", "-con_nsubsidyhalvinginterval", "-con_bip16exception", "-con_bip34height", "-con_bip65height", "-con_bip66height", "-con_npowtargettimespan", "-con_npowtargetspacing", "-con_nrulechangeactivationthreshold", "-con_nminerconfirmationwindow", "-con_powlimit", "-con_bip34hash", "-con_nminimumchainwork", "-con_defaultassumevalid", "-npruneafterheight", "-fdefaultconsistencychecks", "-fmineblocksondemand", "-bech32_hrp", "-fallback_fee_enabled", "-pubkeyprefix", "-scriptprefix", "-secretprefix", "-extpubkeyprefix", "-extprvkeyprefix", "-pchmessagestart",
         // GUI args. These will be overwritten by SetupUIArgs for the GUI
         "-allowselfsignedrootcertificates", "-choosedatadir", "-lang=<lang>", "-min", "-resetguisettings", "-rootcertificates=<file>", "-splash", "-uiplatform"};
 
diff --git a/test/lint/check-doc.py b/test/lint/check-doc.py
index ab8e0e57d1..b39af1dbd5 100755
--- a/test/lint/check-doc.py
+++ b/test/lint/check-doc.py
@@ -24,6 +24,8 @@ CMD_GREP_DOCS = r"git grep --perl-regexp '{}' {}".format(REGEX_DOC, CMD_ROOT_DIR
 # list unsupported, deprecated and duplicate args as they need no documentation
 SET_DOC_OPTIONAL = set(['-rpcssl', '-benchmark', '-h', '-help', '-socks', '-tor', '-debugnet', '-whitelistalwaysrelay', '-promiscuousmempoolflags', '-blockminsize', '-dbcrashratio', '-forcecompactdb', '-usehd'])
 
+SET_DOC_OPTIONAL.update(['-con_fpowallowmindifficultyblocks', '-con_fpownoretargeting', '-con_nsubsidyhalvinginterval', '-con_bip16exception', '-con_bip34height', '-con_bip65height', '-con_bip66height', '-con_npowtargettimespan', '-con_npowtargetspacing', '-con_nrulechangeactivationthreshold', '-con_nminerconfirmationwindow', '-con_powlimit', '-con_bip34hash', '-con_nminimumchainwork', '-con_defaultassumevalid', '-npruneafterheight', '-fdefaultconsistencychecks', '-fmineblocksondemand', '-bech32_hrp', '-fallback_fee_enabled', '-pubkeyprefix', '-scriptprefix', '-secretprefix', '-extpubkeyprefix', '-extprvkeyprefix', '-pchmessagestart'])
+
 
 def main():
     used = check_output(CMD_GREP_ARGS, shell=True, universal_newlines=True)