diff --git a/src/policy/policy.cpp b/src/policy/policy.cpp
index c706d71df..788ae786d 100644
--- a/src/policy/policy.cpp
+++ b/src/policy/policy.cpp
@@ -1,198 +1,200 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 // NOTE: This file is intended to be customised by the end user, and includes
 // only local node policy logic
 
 #include <policy/policy.h>
 
 #include <script/interpreter.h>
 #include <tinyformat.h>
 #include <util.h>
 #include <utilstrencodings.h>
 #include <validation.h>
 
 Amount GetDustThreshold(const CTxOut &txout, const CFeeRate &dustRelayFeeIn) {
     /**
      * "Dust" is defined in terms of dustRelayFee, which has units
      * satoshis-per-kilobyte. If you'd pay more than 1/3 in fees to spend
      * something, then we consider it dust.  A typical spendable txout is 34
      * bytes big, and will need a CTxIn of at least 148 bytes to spend: so dust
      * is a spendable txout less than 546*dustRelayFee/1000 (in satoshis).
      */
     if (txout.scriptPubKey.IsUnspendable()) {
         return Amount::zero();
     }
 
     size_t nSize = GetSerializeSize(txout, SER_DISK, 0);
 
     // the 148 mentioned above
     nSize += (32 + 4 + 1 + 107 + 4);
 
     return 3 * dustRelayFeeIn.GetFee(nSize);
 }
 
 bool IsDust(const CTxOut &txout, const CFeeRate &dustRelayFeeIn) {
     return (txout.nValue < GetDustThreshold(txout, dustRelayFeeIn));
 }
 
-/**
- * Check transaction inputs to mitigate two potential denial-of-service attacks:
- *
- * 1. scriptSigs with extra data stuffed into them, not consumed by scriptPubKey
- * (or P2SH script)
- * 2. P2SH scripts with a crazy number of expensive CHECKSIG/CHECKMULTISIG
- * operations
- *
- * Why bother? To avoid denial-of-service attacks; an attacker can submit a
- * standard HASH... OP_EQUAL transaction, which will get accepted into blocks.
- * The redemption script can be anything; an attacker could use a very
- * expensive-to-check-upon-redemption script like:
- *   DUP CHECKSIG DROP ... repeated 100 times... OP_1
- */
 bool IsStandard(const CScript &scriptPubKey, txnouttype &whichType) {
     std::vector<std::vector<uint8_t>> vSolutions;
     if (!Solver(scriptPubKey, whichType, vSolutions)) {
         return false;
     }
 
     if (whichType == TX_MULTISIG) {
         uint8_t m = vSolutions.front()[0];
         uint8_t n = vSolutions.back()[0];
         // Support up to x-of-3 multisig txns as standard
         if (n < 1 || n > 3) return false;
         if (m < 1 || m > n) return false;
     } else if (whichType == TX_NULL_DATA) {
         if (!fAcceptDatacarrier) {
             return false;
         }
 
         unsigned nMaxDatacarrierBytes =
             gArgs.GetArg("-datacarriersize", MAX_OP_RETURN_RELAY);
         if (scriptPubKey.size() > nMaxDatacarrierBytes) {
             return false;
         }
     }
 
     return whichType != TX_NONSTANDARD;
 }
 
 bool IsStandardTx(const CTransaction &tx, std::string &reason) {
     if (tx.nVersion > CTransaction::MAX_STANDARD_VERSION || tx.nVersion < 1) {
         reason = "version";
         return false;
     }
 
     // Extremely large transactions with lots of inputs can cost the network
     // almost as much to process as they cost the sender in fees, because
     // computing signature hashes is O(ninputs*txsize). Limiting transactions
     // to MAX_STANDARD_TX_SIZE mitigates CPU exhaustion attacks.
     uint32_t sz = tx.GetTotalSize();
     if (sz >= MAX_STANDARD_TX_SIZE) {
         reason = "tx-size";
         return false;
     }
 
     for (const CTxIn &txin : tx.vin) {
         if (txin.scriptSig.size() > MAX_TX_IN_SCRIPT_SIG_SIZE) {
             reason = "scriptsig-size";
             return false;
         }
         if (!txin.scriptSig.IsPushOnly()) {
             reason = "scriptsig-not-pushonly";
             return false;
         }
     }
 
     unsigned int nDataOut = 0;
     txnouttype whichType;
     for (const CTxOut &txout : tx.vout) {
         if (!::IsStandard(txout.scriptPubKey, whichType)) {
             reason = "scriptpubkey";
             return false;
         }
 
         if (whichType == TX_NULL_DATA) {
             nDataOut++;
         } else if ((whichType == TX_MULTISIG) && (!fIsBareMultisigStd)) {
             reason = "bare-multisig";
             return false;
         } else if (IsDust(txout, ::dustRelayFee)) {
             reason = "dust";
             return false;
         }
     }
 
     // only one OP_RETURN txout is permitted
     if (nDataOut > 1) {
         reason = "multi-op-return";
         return false;
     }
 
     return true;
 }
 
+/**
+ * Check transaction inputs to mitigate two
+ * potential denial-of-service attacks:
+ *
+ * 1. scriptSigs with extra data stuffed into them,
+ *    not consumed by scriptPubKey (or P2SH script)
+ * 2. P2SH scripts with a crazy number of expensive
+ *    CHECKSIG/CHECKMULTISIG operations
+ *
+ * Why bother? To avoid denial-of-service attacks; an attacker
+ * can submit a standard HASH... OP_EQUAL transaction,
+ * which will get accepted into blocks. The redemption
+ * script can be anything; an attacker could use a very
+ * expensive-to-check-upon-redemption script like:
+ *   DUP CHECKSIG DROP ... repeated 100 times... OP_1
+ */
 bool AreInputsStandard(const CTransaction &tx,
                        const CCoinsViewCache &mapInputs) {
     if (tx.IsCoinBase()) {
         // Coinbases don't use vin normally.
         return true;
     }
 
     for (const CTxIn &in : tx.vin) {
         const CTxOut &prev = mapInputs.GetOutputFor(in);
 
         std::vector<std::vector<uint8_t>> vSolutions;
         txnouttype whichType;
         // get the scriptPubKey corresponding to this input:
         const CScript &prevScript = prev.scriptPubKey;
         if (!Solver(prevScript, whichType, vSolutions)) {
             return false;
         }
 
         if (whichType == TX_SCRIPTHASH) {
             std::vector<std::vector<uint8_t>> stack;
             // convert the scriptSig into a stack, so we can inspect the
             // redeemScript
             if (!EvalScript(stack, in.scriptSig, SCRIPT_VERIFY_NONE,
                             BaseSignatureChecker())) {
                 return false;
             }
             if (stack.empty()) {
                 return false;
             }
 
             CScript subscript(stack.back().begin(), stack.back().end());
             if (subscript.GetSigOpCount(STANDARD_SCRIPT_VERIFY_FLAGS, true) >
                 MAX_P2SH_SIGOPS) {
                 return false;
             }
         }
     }
 
     return true;
 }
 
 CFeeRate dustRelayFee = CFeeRate(DUST_RELAY_TX_FEE);
 uint32_t nBytesPerSigOp = DEFAULT_BYTES_PER_SIGOP;
 
 int64_t GetVirtualTransactionSize(int64_t nSize, int64_t nSigOpCost,
                                   unsigned int bytes_per_sigop) {
     return nSize;
 }
 
 int64_t GetVirtualTransactionSize(const CTransaction &tx, int64_t nSigOpCost,
                                   unsigned int bytes_per_sigop) {
     return GetVirtualTransactionSize(
         ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION), nSigOpCost,
         bytes_per_sigop);
 }
 
 int64_t GetVirtualTransactionInputSize(const CTxIn &txin, int64_t nSigOpCost,
                                        unsigned int bytes_per_sigop) {
     return GetVirtualTransactionSize(
         ::GetSerializeSize(txin, SER_NETWORK, PROTOCOL_VERSION), nSigOpCost,
         bytes_per_sigop);
 }