diff --git a/contracts/ModuleRegistry.sol b/contracts/ModuleRegistry.sol
index ec204914a..59a02af74 100644
--- a/contracts/ModuleRegistry.sol
+++ b/contracts/ModuleRegistry.sol
@@ -35,6 +35,14 @@ contract ModuleRegistry is IModuleRegistry, EternalStorage {
 
     */
 
+    bytes32 constant INITIALIZE = 0x9ef7257c3339b099aacf96e55122ee78fb65a36bd2a6c19249882be9c98633bf; //keccak256("initialised")
+    bytes32 constant POLYTOKEN = 0xacf8fbd51bb4b83ba426cdb12f63be74db97c412515797993d2a385542e311d7; //keccak256("polyToken")
+    bytes32 constant PAUSED = 0xee35723ac350a69d2a92d3703f17439cbaadf2f093a21ba5bf5f1a53eb2a14d9; //keccak256("paused")
+    bytes32 constant OWNER = 0x02016836a56b71f0d02689e69e326f4f4c1b9057164ef592671cf0d37c8040c0; //keccak256("owner")
+    bytes32 constant POLYMATHREGISTRY = 0x90eeab7c36075577c7cc5ff366e389fefa8a18289b949bab3529ab4471139d4d; //keccak256("polymathRegistry")
+    bytes32 constant FEATURE_REGISTRY = 0xed9ca06607835ad25ecacbcb97f2bc414d4a51ecf391b5ae42f15991227ab146; //keccak256("featureRegistry")
+    bytes32 constant SECURITY_TOKEN_REGISTRY = 0x12ada4f7ee6c2b7b933330be61fefa007a1f497dc8df1b349b48071a958d7a81; //keccak256("securityTokenRegistry")
+
     ///////////
     // Events
     //////////
@@ -105,12 +113,12 @@ contract ModuleRegistry is IModuleRegistry, EternalStorage {
     }
 
     function initialize(address _polymathRegistry, address _owner) external payable {
-        require(!getBoolValue(Encoder.getKey("initialised")), "already initialized");
+        require(!getBoolValue(INITIALIZE), "already initialized");
         require(_owner != address(0) && _polymathRegistry != address(0), "0x address is invalid");
-        set(Encoder.getKey("polymathRegistry"), _polymathRegistry);
-        set(Encoder.getKey("owner"), _owner);
-        set(Encoder.getKey("paused"), false);
-        set(Encoder.getKey("initialised"), true);
+        set(POLYMATHREGISTRY, _polymathRegistry);
+        set(OWNER, _owner);
+        set(PAUSED, false);
+        set(INITIALIZE, true);
     }
 
     /**
@@ -122,7 +130,7 @@ contract ModuleRegistry is IModuleRegistry, EternalStorage {
      * @param _isUpgrade whether or not the function is being called as a result of an upgrade
      */
     function useModule(address _moduleFactory, bool _isUpgrade) external {
-        if (IFeatureRegistry(getAddressValue(Encoder.getKey("featureRegistry"))).getFeatureStatus("customModulesAllowed")) {
+        if (IFeatureRegistry(getAddressValue(FEATURE_REGISTRY)).getFeatureStatus("customModulesAllowed")) {
             require(
                 getBoolValue(Encoder.getKey("verified", _moduleFactory)) || IOwnable(_moduleFactory).owner() == IOwnable(msg.sender).owner(),
                 "ModuleFactory must be verified or SecurityToken owner must be ModuleFactory owner"
@@ -132,7 +140,7 @@ contract ModuleRegistry is IModuleRegistry, EternalStorage {
         }
         // This if statement is required to be able to add modules from the STFactory contract during deployment
         // before the token has been registered to the STR.
-        if (ISecurityTokenRegistry(getAddressValue(Encoder.getKey("securityTokenRegistry"))).isSecurityToken(msg.sender)) {
+        if (ISecurityTokenRegistry(getAddressValue(SECURITY_TOKEN_REGISTRY)).isSecurityToken(msg.sender)) {
             require(isCompatibleModule(_moduleFactory, msg.sender), "Incompatible versions");
             if (!_isUpgrade) {
                 pushArray(Encoder.getKey("reputation", _moduleFactory), msg.sender);
@@ -161,7 +169,7 @@ contract ModuleRegistry is IModuleRegistry, EternalStorage {
      * @param _moduleFactory is the address of the module factory to be registered
      */
     function registerModule(address _moduleFactory) external whenNotPausedOrOwner {
-        if (IFeatureRegistry(getAddressValue(Encoder.getKey("featureRegistry"))).getFeatureStatus("customModulesAllowed")) {
+        if (IFeatureRegistry(getAddressValue(FEATURE_REGISTRY)).getFeatureStatus("customModulesAllowed")) {
             require(
                 msg.sender == IOwnable(_moduleFactory).owner() || msg.sender == owner(),
                 "msg.sender must be the Module Factory owner or registry curator"
@@ -337,7 +345,7 @@ contract ModuleRegistry is IModuleRegistry, EternalStorage {
     function getModulesByTypeAndToken(uint8 _moduleType, address _securityToken) public view returns(address[] memory) {
         address[] memory _addressList = getArrayAddress(Encoder.getKey("moduleList", uint256(_moduleType)));
         uint256 _len = _addressList.length;
-        bool _isCustomModuleAllowed = IFeatureRegistry(getAddressValue(Encoder.getKey("featureRegistry"))).getFeatureStatus(
+        bool _isCustomModuleAllowed = IFeatureRegistry(getAddressValue(FEATURE_REGISTRY)).getFeatureStatus(
             "customModulesAllowed"
         );
         uint256 counter = 0;
@@ -387,7 +395,7 @@ contract ModuleRegistry is IModuleRegistry, EternalStorage {
      * @notice Called by the owner to pause, triggers stopped state
      */
     function pause() external whenNotPaused onlyOwner {
-        set(Encoder.getKey("paused"), true);
+        set(PAUSED, true);
         /*solium-disable-next-line security/no-block-members*/
         emit Pause(msg.sender);
     }
@@ -396,7 +404,7 @@ contract ModuleRegistry is IModuleRegistry, EternalStorage {
      * @notice Called by the owner to unpause, returns to normal state
      */
     function unpause() external whenPaused onlyOwner {
-        set(Encoder.getKey("paused"), false);
+        set(PAUSED, false);
         /*solium-disable-next-line security/no-block-members*/
         emit Unpause(msg.sender);
     }
@@ -405,10 +413,10 @@ contract ModuleRegistry is IModuleRegistry, EternalStorage {
      * @notice Stores the contract addresses of other key contracts from the PolymathRegistry
      */
     function updateFromRegistry() external onlyOwner {
-        address _polymathRegistry = getAddressValue(Encoder.getKey("polymathRegistry"));
-        set(Encoder.getKey("securityTokenRegistry"), IPolymathRegistry(_polymathRegistry).getAddress("SecurityTokenRegistry"));
-        set(Encoder.getKey("featureRegistry"), IPolymathRegistry(_polymathRegistry).getAddress("FeatureRegistry"));
-        set(Encoder.getKey("polyToken"), IPolymathRegistry(_polymathRegistry).getAddress("PolyToken"));
+        address _polymathRegistry = getAddressValue(POLYMATHREGISTRY);
+        set(SECURITY_TOKEN_REGISTRY, IPolymathRegistry(_polymathRegistry).getAddress("SecurityTokenRegistry"));
+        set(FEATURE_REGISTRY, IPolymathRegistry(_polymathRegistry).getAddress("FeatureRegistry"));
+        set(POLYTOKEN, IPolymathRegistry(_polymathRegistry).getAddress("PolyToken"));
     }
 
     /**
@@ -418,7 +426,7 @@ contract ModuleRegistry is IModuleRegistry, EternalStorage {
     function transferOwnership(address _newOwner) external onlyOwner {
         require(_newOwner != address(0), "Invalid address");
         emit OwnershipTransferred(owner(), _newOwner);
-        set(Encoder.getKey("owner"), _newOwner);
+        set(OWNER, _newOwner);
     }
 
     /**
@@ -426,7 +434,7 @@ contract ModuleRegistry is IModuleRegistry, EternalStorage {
      * @return address owner
      */
     function owner() public view returns(address) {
-        return getAddressValue(Encoder.getKey("owner"));
+        return getAddressValue(OWNER);
     }
 
     /**
@@ -434,6 +442,6 @@ contract ModuleRegistry is IModuleRegistry, EternalStorage {
      * @return bool
      */
     function isPaused() public view returns(bool) {
-        return getBoolValue(Encoder.getKey("paused"));
+        return getBoolValue(PAUSED);
     }
 }
diff --git a/contracts/RegistryUpdater.sol b/contracts/RegistryUpdater.sol
deleted file mode 100644
index 70e6c6849..000000000
--- a/contracts/RegistryUpdater.sol
+++ /dev/null
@@ -1,25 +0,0 @@
-pragma solidity ^0.5.0;
-
-import "openzeppelin-solidity/contracts/ownership/Ownable.sol";
-import "./PolymathRegistry.sol";
-
-contract RegistryUpdater is Ownable {
-    address public polymathRegistry;
-    address public moduleRegistry;
-    address public securityTokenRegistry;
-    address public featureRegistry;
-    address public polyToken;
-
-    constructor(address _polymathRegistry) public {
-        require(_polymathRegistry != address(0), "Invalid address");
-        polymathRegistry = _polymathRegistry;
-    }
-
-    function updateFromRegistry() public onlyOwner {
-        moduleRegistry = PolymathRegistry(polymathRegistry).getAddress("ModuleRegistry");
-        securityTokenRegistry = PolymathRegistry(polymathRegistry).getAddress("SecurityTokenRegistry");
-        featureRegistry = PolymathRegistry(polymathRegistry).getAddress("FeatureRegistry");
-        polyToken = PolymathRegistry(polymathRegistry).getAddress("PolyToken");
-    }
-
-}
diff --git a/contracts/SecurityTokenRegistry.sol b/contracts/SecurityTokenRegistry.sol
index b9fd76ff2..533a40c63 100644
--- a/contracts/SecurityTokenRegistry.sol
+++ b/contracts/SecurityTokenRegistry.sol
@@ -67,16 +67,18 @@ contract SecurityTokenRegistry is EternalStorage, Proxy {
 
     using SafeMath for uint256;
 
-    bytes32 constant INITIALIZE = 0x9ef7257c3339b099aacf96e55122ee78fb65a36bd2a6c19249882be9c98633bf;
-    bytes32 constant POLYTOKEN = 0xacf8fbd51bb4b83ba426cdb12f63be74db97c412515797993d2a385542e311d7;
-    bytes32 constant STLAUNCHFEE = 0xd677304bb45536bb7fdfa6b9e47a3c58fe413f9e8f01474b0a4b9c6e0275baf2;
-    bytes32 constant TICKERREGFEE = 0x2fcc69711628630fb5a42566c68bd1092bc4aa26826736293969fddcd11cb2d2;
-    bytes32 constant EXPIRYLIMIT = 0x604268e9a73dfd777dcecb8a614493dd65c638bad2f5e7d709d378bd2fb0baee;
-    bytes32 constant PAUSED = 0xee35723ac350a69d2a92d3703f17439cbaadf2f093a21ba5bf5f1a53eb2a14d9;
-    bytes32 constant OWNER = 0x02016836a56b71f0d02689e69e326f4f4c1b9057164ef592671cf0d37c8040c0;
-    bytes32 constant POLYMATHREGISTRY = 0x90eeab7c36075577c7cc5ff366e389fefa8a18289b949bab3529ab4471139d4d;
-    bytes32 constant STRGETTER = 0x982f24b3bd80807ec3cb227ba152e15c07d66855fa8ae6ca536e689205c0e2e9;
+    bytes32 constant INITIALIZE = 0x9ef7257c3339b099aacf96e55122ee78fb65a36bd2a6c19249882be9c98633bf; //keccak256("initialised")
+    bytes32 constant POLYTOKEN = 0xacf8fbd51bb4b83ba426cdb12f63be74db97c412515797993d2a385542e311d7; //keccak256("polyToken")
+    bytes32 constant STLAUNCHFEE = 0xd677304bb45536bb7fdfa6b9e47a3c58fe413f9e8f01474b0a4b9c6e0275baf2; //keccak256("stLaunchFee")
+    bytes32 constant TICKERREGFEE = 0x2fcc69711628630fb5a42566c68bd1092bc4aa26826736293969fddcd11cb2d2; //keccak256("tickerRegFee")
+    bytes32 constant EXPIRYLIMIT = 0x604268e9a73dfd777dcecb8a614493dd65c638bad2f5e7d709d378bd2fb0baee; //keccak256("expiryLimit")
+    bytes32 constant PAUSED = 0xee35723ac350a69d2a92d3703f17439cbaadf2f093a21ba5bf5f1a53eb2a14d9; //keccak256("paused")
+    bytes32 constant OWNER = 0x02016836a56b71f0d02689e69e326f4f4c1b9057164ef592671cf0d37c8040c0; //keccak256("owner")
+    bytes32 constant POLYMATHREGISTRY = 0x90eeab7c36075577c7cc5ff366e389fefa8a18289b949bab3529ab4471139d4d; //keccak256("polymathRegistry")
+    bytes32 constant STRGETTER = 0x982f24b3bd80807ec3cb227ba152e15c07d66855fa8ae6ca536e689205c0e2e9; //keccak256("STRGetter")
     bytes32 constant IS_FEE_IN_POLY = 0x7152e5426955da44af11ecd67fec5e2a3ba747be974678842afa9394b9a075b6; //keccak256("IS_FEE_IN_POLY")
+    bytes32 constant ACTIVE_USERS = 0x425619ce6ba8e9f80f17c0ef298b6557e321d70d7aeff2e74dd157bd87177a9e; //keccak256("activeUsers")
+    bytes32 constant LATEST_VERSION = 0x4c63b69b9117452b9f11af62077d0cda875fb4e2dbe07ad6f31f728de6926230; //keccak256("latestVersion")
 
     string constant POLY_ORACLE = "StablePolyUsdOracle";
 
@@ -196,7 +198,6 @@ contract SecurityTokenRegistry is EternalStorage, Proxy {
         address _getterContract
     )
         public
-        payable
     {
         require(!getBoolValue(INITIALIZE),"Initialized");
         require(
@@ -264,7 +265,7 @@ contract SecurityTokenRegistry is EternalStorage, Proxy {
     }
 
     function _implementation() internal view returns(address) {
-        return getAddressValue(Encoder.getKey("STRGetter"));
+        return getAddressValue(STRGETTER);
     }
 
     /////////////////////////////
@@ -422,7 +423,7 @@ contract SecurityTokenRegistry is EternalStorage, Proxy {
         set(Encoder.getKey("tickerIndex", _ticker), length);
         bytes32 seenKey = Encoder.getKey("seenUsers", _owner);
         if (!getBoolValue(seenKey)) {
-            pushArray(Encoder.getKey("activeUsers"), _owner);
+            pushArray(ACTIVE_USERS, _owner);
             set(seenKey, true);
         }
     }
@@ -528,7 +529,7 @@ contract SecurityTokenRegistry is EternalStorage, Proxy {
         require(bytes(_name).length > 0 && bytes(_ticker).length > 0, "Bad ticker");
         require(_treasuryWallet != address(0), "0x0 not allowed");
         if (_protocolVersion == 0) {
-            protocolVersion = getUintValue(Encoder.getKey("latestVersion"));
+            protocolVersion = getUintValue(LATEST_VERSION);
         }
         require(protocolVersion != uint256(0), "Invalid version");
         string memory ticker = Util.upper(_ticker);
@@ -572,7 +573,7 @@ contract SecurityTokenRegistry is EternalStorage, Proxy {
         address stOwner = IOwnable(st).owner();
         require(msg.sender == stOwner, "Unauthroized");
         require(ISecurityToken(st).transfersFrozen(), "Transfers not frozen");
-        uint256 protocolVersion = getUintValue(Encoder.getKey("latestVersion"));
+        uint256 protocolVersion = getUintValue(LATEST_VERSION);
         address newSecurityTokenAddress =
             _deployToken(_name, ticker, _tokenDetails, stOwner, _divisible, _treasuryWallet, protocolVersion);
         emit SecurityTokenRefreshed(
@@ -777,7 +778,6 @@ contract SecurityTokenRegistry is EternalStorage, Proxy {
     function _setProtocolFactory(address _STFactoryAddress, uint8 _major, uint8 _minor, uint8 _patch) internal {
         require(_STFactoryAddress != address(0), "Bad address");
         uint24 _packedVersion = VersionUtils.pack(_major, _minor, _patch);
-        //set(Encoder.getKey("latestVersion"), uint256(_packedVersion));
         set(Encoder.getKey("protocolVersionST", uint256(_packedVersion)), _STFactoryAddress);
         emit ProtocolFactorySet(_STFactoryAddress, _major, _minor, _patch);
     }
@@ -790,7 +790,7 @@ contract SecurityTokenRegistry is EternalStorage, Proxy {
     */
     function removeProtocolFactory(uint8 _major, uint8 _minor, uint8 _patch) public onlyOwner {
         uint24 _packedVersion = VersionUtils.pack(_major, _minor, _patch);
-        require(getUintValue(Encoder.getKey("latestVersion")) != _packedVersion, "Cannot remove latestVersion");
+        require(getUintValue(LATEST_VERSION) != _packedVersion, "Cannot remove latestVersion");
         emit ProtocolFactoryRemoved(getAddressValue(Encoder.getKey("protocolVersionST", _packedVersion)), _major, _minor, _patch);
         set(Encoder.getKey("protocolVersionST", uint256(_packedVersion)), address(0));
     }
@@ -810,7 +810,7 @@ contract SecurityTokenRegistry is EternalStorage, Proxy {
     function _setLatestVersion(uint8 _major, uint8 _minor, uint8 _patch) internal {
         uint24 _packedVersion = VersionUtils.pack(_major, _minor, _patch);
         require(getAddressValue(Encoder.getKey("protocolVersionST", _packedVersion)) != address(0), "No factory");
-        set(Encoder.getKey("latestVersion"), uint256(_packedVersion));
+        set(LATEST_VERSION, uint256(_packedVersion));
         emit LatestVersionSet(_major, _minor, _patch);
     }
 
diff --git a/contracts/datastore/DataStore.sol b/contracts/datastore/DataStore.sol
index 1d12c13d8..50a397838 100644
--- a/contracts/datastore/DataStore.sol
+++ b/contracts/datastore/DataStore.sol
@@ -164,28 +164,28 @@ contract DataStore is DataStoreStorage, IDataStore {
      * @param _keys Array of keys to identify the data
      * @param _data Array of data to be stored against the respective keys
      */
-    function setUint256Multi(bytes32[] calldata _keys, uint256[] calldata _data) external validArrayLength(_keys.length, _data.length) {
+    function setUint256Multi(bytes32[] memory _keys, uint256[] memory _data) public validArrayLength(_keys.length, _data.length) {
         _isAuthorized();
         for (uint256 i = 0; i < _keys.length; i++) {
             _setData(_keys[i], _data[i], false);
         }
     }
 
-    function setBytes32Multi(bytes32[] calldata _keys, bytes32[] calldata _data) external validArrayLength(_keys.length, _data.length) {
+    function setBytes32Multi(bytes32[] memory _keys, bytes32[] memory _data) public validArrayLength(_keys.length, _data.length) {
         _isAuthorized();
         for (uint256 i = 0; i < _keys.length; i++) {
             _setData(_keys[i], _data[i], false);
         }
     }
 
-    function setAddressMulti(bytes32[] calldata _keys, address[] calldata _data) external validArrayLength(_keys.length, _data.length) {
+    function setAddressMulti(bytes32[] memory _keys, address[] memory _data) public validArrayLength(_keys.length, _data.length) {
         _isAuthorized();
         for (uint256 i = 0; i < _keys.length; i++) {
             _setData(_keys[i], _data[i], false);
         }
     }
 
-    function setBoolMulti(bytes32[] calldata _keys, bool[] calldata _data) external validArrayLength(_keys.length, _data.length) {
+    function setBoolMulti(bytes32[] memory _keys, bool[] memory _data) public validArrayLength(_keys.length, _data.length) {
         _isAuthorized();
         for (uint256 i = 0; i < _keys.length; i++) {
             _setData(_keys[i], _data[i], false);
@@ -197,28 +197,28 @@ contract DataStore is DataStoreStorage, IDataStore {
      * @param _keys Array of keys to identify the data
      * @param _data Array of data to be inserted in arrays of the respective keys
      */
-    function insertUint256Multi(bytes32[] calldata _keys, uint256[] calldata _data) external validArrayLength(_keys.length, _data.length) {
+    function insertUint256Multi(bytes32[] memory _keys, uint256[] memory _data) public validArrayLength(_keys.length, _data.length) {
         _isAuthorized();
         for (uint256 i = 0; i < _keys.length; i++) {
             _setData(_keys[i], _data[i], true);
         }
     }
 
-    function insertBytes32Multi(bytes32[] calldata _keys, bytes32[] calldata _data) external validArrayLength(_keys.length, _data.length) {
+    function insertBytes32Multi(bytes32[] memory _keys, bytes32[] memory _data) public validArrayLength(_keys.length, _data.length) {
         _isAuthorized();
         for (uint256 i = 0; i < _keys.length; i++) {
             _setData(_keys[i], _data[i], true);
         }
     }
 
-    function insertAddressMulti(bytes32[] calldata _keys, address[] calldata _data) external validArrayLength(_keys.length, _data.length) {
+    function insertAddressMulti(bytes32[] memory _keys, address[] memory _data) public validArrayLength(_keys.length, _data.length) {
         _isAuthorized();
         for (uint256 i = 0; i < _keys.length; i++) {
             _setData(_keys[i], _data[i], true);
         }
     }
 
-    function insertBoolMulti(bytes32[] calldata _keys, bool[] calldata _data) external validArrayLength(_keys.length, _data.length) {
+    function insertBoolMulti(bytes32[] memory _keys, bool[] memory _data) public validArrayLength(_keys.length, _data.length) {
         _isAuthorized();
         for (uint256 i = 0; i < _keys.length; i++) {
             _setData(_keys[i], _data[i], true);
@@ -297,7 +297,7 @@ contract DataStore is DataStoreStorage, IDataStore {
         return boolArrayData[_key][_index];
     }
 
-    function getUint256ArrayElements(bytes32 _key, uint256 _startIndex, uint256 _endIndex) external view returns(uint256[] memory array) {
+    function getUint256ArrayElements(bytes32 _key, uint256 _startIndex, uint256 _endIndex) public view returns(uint256[] memory array) {
         uint256 size = uintArrayData[_key].length;
         if (_endIndex >= size) {
             size = size - _startIndex;
@@ -309,7 +309,7 @@ contract DataStore is DataStoreStorage, IDataStore {
             array[i] = uintArrayData[_key][i + _startIndex];
     }
 
-    function getBytes32ArrayElements(bytes32 _key, uint256 _startIndex, uint256 _endIndex) external view returns(bytes32[] memory array) {
+    function getBytes32ArrayElements(bytes32 _key, uint256 _startIndex, uint256 _endIndex) public view returns(bytes32[] memory array) {
         uint256 size = bytes32ArrayData[_key].length;
         if (_endIndex >= size) {
             size = size - _startIndex;
@@ -321,7 +321,7 @@ contract DataStore is DataStoreStorage, IDataStore {
             array[i] = bytes32ArrayData[_key][i + _startIndex];
     }
 
-    function getAddressArrayElements(bytes32 _key, uint256 _startIndex, uint256 _endIndex) external view returns(address[] memory array) {
+    function getAddressArrayElements(bytes32 _key, uint256 _startIndex, uint256 _endIndex) public view returns(address[] memory array) {
         uint256 size = addressArrayData[_key].length;
         if (_endIndex >= size) {
             size = size - _startIndex;
@@ -333,7 +333,7 @@ contract DataStore is DataStoreStorage, IDataStore {
             array[i] = addressArrayData[_key][i + _startIndex];
     }
 
-    function getBoolArrayElements(bytes32 _key, uint256 _startIndex, uint256 _endIndex) external view returns(bool[] memory array) {
+    function getBoolArrayElements(bytes32 _key, uint256 _startIndex, uint256 _endIndex) public view returns(bool[] memory array) {
         uint256 size = boolArrayData[_key].length;
         if (_endIndex >= size) {
             size = size - _startIndex;
diff --git a/contracts/interfaces/ISecurityToken.sol b/contracts/interfaces/ISecurityToken.sol
index c3ccef5bc..7fba2be46 100644
--- a/contracts/interfaces/ISecurityToken.sol
+++ b/contracts/interfaces/ISecurityToken.sol
@@ -539,6 +539,12 @@ interface ISecurityToken {
       */
     function granularity() external view returns(uint256);
 
+    /**
+      * @notice Provides the address of the polymathRegistry
+      * @return address
+      */
+    function polymathRegistry() external view returns(address);
+
     /**
     * @notice Upgrades a module attached to the SecurityToken
     * @param _module address of module to archive
diff --git a/contracts/libraries/DecimalMath.sol b/contracts/libraries/DecimalMath.sol
index ab942bad2..92abcc7de 100644
--- a/contracts/libraries/DecimalMath.sol
+++ b/contracts/libraries/DecimalMath.sol
@@ -5,12 +5,14 @@ import "openzeppelin-solidity/contracts/math/SafeMath.sol";
 library DecimalMath {
     using SafeMath for uint256;
 
+    uint256 internal constant e18 = uint256(10) ** uint256(18);
+
     /**
      * @notice This function multiplies two decimals represented as (decimal * 10**DECIMALS)
      * @return uint256 Result of multiplication represented as (decimal * 10**DECIMALS)
      */
     function mul(uint256 x, uint256 y) internal pure returns(uint256 z) {
-        z = SafeMath.add(SafeMath.mul(x, y), (10 ** 18) / 2) / (10 ** 18);
+        z = SafeMath.add(SafeMath.mul(x, y), (e18) / 2) / (e18);
     }
 
     /**
@@ -18,7 +20,7 @@ library DecimalMath {
      * @return uint256 Result of division represented as (decimal * 10**DECIMALS)
      */
     function div(uint256 x, uint256 y) internal pure returns(uint256 z) {
-        z = SafeMath.add(SafeMath.mul(x, (10 ** 18)), y / 2) / y;
+        z = SafeMath.add(SafeMath.mul(x, (e18)), y / 2) / y;
     }
 
 }
diff --git a/contracts/libraries/TokenLib.sol b/contracts/libraries/TokenLib.sol
index e627aea74..e0f318fa9 100644
--- a/contracts/libraries/TokenLib.sol
+++ b/contracts/libraries/TokenLib.sol
@@ -364,7 +364,7 @@ library TokenLib {
         bytes32 name,
         string memory uri,
         bytes32 documentHash
-    )   
+    )
         public
     {
         require(name != bytes32(0), "Bad name");
@@ -388,7 +388,7 @@ library TokenLib {
         mapping(bytes32 => uint256) storage docIndexes,
         bytes32 name
     )
-        public 
+        public
     {
         require(document[name].lastModified != uint256(0), "Not existed");
         uint256 index = docIndexes[name] - 1;
@@ -460,24 +460,25 @@ library TokenLib {
         bytes32 appCode,
         address to,
         uint256 value,
-        uint256 balanceOfFrom,
-        uint256 balanceOfTo
-    )   
+        uint256 balanceOfFrom
+    )
         public
-        pure 
-        returns (bool, byte, bytes32) 
+        pure
+        returns (bool, byte, bytes32)
     {
         if (!success)
             return (false, 0x50, appCode);
 
-        else if (balanceOfFrom < value)
+        if (balanceOfFrom < value)
             return (false, 0x52, bytes32(0));
 
-        else if (to == address(0))
+        if (to == address(0))
             return (false, 0x57, bytes32(0));
 
-        else if (!KindMath.checkAdd(balanceOfTo, value))
-            return (false, 0x50, bytes32(0));
+        // Balance overflow can never happen due to totalsupply being a uint256 as well
+        // else if (!KindMath.checkAdd(balanceOf(_to), _value))
+        //     return (false, 0x50, bytes32(0));
+
         return (true, 0x51, bytes32(0));
     }
 
diff --git a/contracts/mocks/MockSecurityTokenLogic.sol b/contracts/mocks/MockSecurityTokenLogic.sol
index b87b75fad..814ab7bbb 100644
--- a/contracts/mocks/MockSecurityTokenLogic.sol
+++ b/contracts/mocks/MockSecurityTokenLogic.sol
@@ -22,8 +22,6 @@ contract MockSecurityTokenLogic is SecurityToken {
      * @dev Can only be called once
      */
     function upgrade(address _getterDelegate, uint256 _upgrade) external {
-        require(msg.sender == address(this));
-        //Expected to be called atomically with the proxy being created
         getterDelegate = _getterDelegate;
         //securityTokenVersion = SemanticVersion(3, 1, 0);
         emit UpgradeEvent(_upgrade);
@@ -33,4 +31,18 @@ contract MockSecurityTokenLogic is SecurityToken {
         emit UpgradeEvent(_upgrade);
     }
 
+    //To reduce bytecode size
+    function addModuleWithLabel(
+        address /* _moduleFactory */,
+        bytes memory /* _data */,
+        uint256 /* _maxCost */,
+        uint256 /* _budget */,
+        bytes32 /* _label */,
+        bool /* _archived */
+    )
+        public
+    {
+        emit UpgradeEvent(0);
+    }
+
 }
diff --git a/contracts/mocks/SecurityTokenMock.sol b/contracts/mocks/SecurityTokenMock.sol
index 1aaf56864..9f3b6a1d2 100644
--- a/contracts/mocks/SecurityTokenMock.sol
+++ b/contracts/mocks/SecurityTokenMock.sol
@@ -13,4 +13,4 @@ contract SecurityTokenMock is SecurityToken {
         super.initialize(_getterDelegate);
         securityTokenVersion = SemanticVersion(2, 2, 0);
     }
-}
\ No newline at end of file
+}
diff --git a/contracts/modules/Checkpoint/DividendCheckpoint.sol b/contracts/modules/Checkpoint/DividendCheckpoint.sol
index 591aed22a..ee22e1836 100644
--- a/contracts/modules/Checkpoint/DividendCheckpoint.sol
+++ b/contracts/modules/Checkpoint/DividendCheckpoint.sol
@@ -19,6 +19,7 @@ import "openzeppelin-solidity/contracts/math/Math.sol";
  */
 contract DividendCheckpoint is DividendCheckpointStorage, ICheckpoint, Module {
     using SafeMath for uint256;
+    uint256 internal constant e18 = uint256(10) ** uint256(18);
 
     event SetDefaultExcludedAddresses(address[] _excluded);
     event SetWithholding(address[] _investors, uint256[] _withholding);
@@ -123,7 +124,7 @@ contract DividendCheckpoint is DividendCheckpointStorage, ICheckpoint, Module {
         /*solium-disable-next-line security/no-block-members*/
         emit SetWithholding(_investors, _withholding);
         for (uint256 i = 0; i < _investors.length; i++) {
-            require(_withholding[i] <= 10 ** 18, "Incorrect withholding tax");
+            require(_withholding[i] <= e18, "Incorrect withholding tax");
             withholdingTax[_investors[i]] = _withholding[i];
         }
     }
@@ -134,7 +135,7 @@ contract DividendCheckpoint is DividendCheckpointStorage, ICheckpoint, Module {
      * @param _withholding Withholding tax for all investors (multiplied by 10**16)
      */
     function setWithholdingFixed(address[] memory _investors, uint256 _withholding) public withPerm(ADMIN) {
-        require(_withholding <= 10 ** 18, "Incorrect withholding tax");
+        require(_withholding <= e18, "Incorrect withholding tax");
         /*solium-disable-next-line security/no-block-members*/
         emit SetWithholdingFixed(_investors, _withholding);
         for (uint256 i = 0; i < _investors.length; i++) {
@@ -232,7 +233,7 @@ contract DividendCheckpoint is DividendCheckpointStorage, ICheckpoint, Module {
         }
         uint256 balance = ISecurityToken(securityToken).balanceOfAt(_payee, dividend.checkpointId);
         uint256 claim = balance.mul(dividend.amount).div(dividend.totalSupply);
-        uint256 withheld = claim.mul(withholdingTax[_payee]).div(uint256(10 ** 18));
+        uint256 withheld = claim.mul(withholdingTax[_payee]).div(e18);
         return (claim, withheld);
     }
 
diff --git a/contracts/modules/Checkpoint/ERC20/ERC20DividendCheckpoint.sol b/contracts/modules/Checkpoint/ERC20/ERC20DividendCheckpoint.sol
index b4120122d..66756aff5 100644
--- a/contracts/modules/Checkpoint/ERC20/ERC20DividendCheckpoint.sol
+++ b/contracts/modules/Checkpoint/ERC20/ERC20DividendCheckpoint.sol
@@ -162,7 +162,7 @@ contract ERC20DividendCheckpoint is ERC20DividendCheckpointStorage, DividendChec
         require(_token != address(0), "Invalid token");
         require(_checkpointId <= securityTokenInstance.currentCheckpointId(), "Invalid checkpoint");
         require(IERC20(_token).transferFrom(msg.sender, address(this), _amount), "insufficent allowance");
-        require(_name[0] != 0);
+        require(_name != bytes32(0));
         uint256 dividendIndex = dividends.length;
         uint256 currentSupply = securityTokenInstance.totalSupplyAt(_checkpointId);
         require(currentSupply > 0, "Invalid supply");
diff --git a/contracts/modules/Checkpoint/Ether/EtherDividendCheckpoint.sol b/contracts/modules/Checkpoint/Ether/EtherDividendCheckpoint.sol
index 6478f3e55..520e390d5 100644
--- a/contracts/modules/Checkpoint/Ether/EtherDividendCheckpoint.sol
+++ b/contracts/modules/Checkpoint/Ether/EtherDividendCheckpoint.sol
@@ -128,7 +128,7 @@ contract EtherDividendCheckpoint is DividendCheckpoint {
         require(_expiry > now, "Expiry is in the past");
         require(msg.value > 0, "No dividend sent");
         require(_checkpointId <= ISecurityToken(securityToken).currentCheckpointId());
-        require(_name[0] != 0);
+        require(_name[0] != bytes32(0));
         uint256 dividendIndex = dividends.length;
         uint256 currentSupply = ISecurityToken(securityToken).totalSupplyAt(_checkpointId);
         require(currentSupply > 0, "Invalid supply");
diff --git a/contracts/modules/PermissionManager/GeneralPermissionManager.sol b/contracts/modules/PermissionManager/GeneralPermissionManager.sol
index 2ed455c3a..c6b93cb32 100644
--- a/contracts/modules/PermissionManager/GeneralPermissionManager.sol
+++ b/contracts/modules/PermissionManager/GeneralPermissionManager.sol
@@ -62,10 +62,11 @@ contract GeneralPermissionManager is GeneralPermissionManagerStorage, IPermissio
      */
     function deleteDelegate(address _delegate) external withPerm(ADMIN) {
         require(delegateDetails[_delegate] != bytes32(0), "delegate does not exist");
-        for (uint256 i = 0; i < allDelegates.length; i++) {
+        uint256 delegateLen = allDelegates.length;
+        for (uint256 i = 0; i < delegateLen; i++) {
             if (allDelegates[i] == _delegate) {
-                allDelegates[i] = allDelegates[allDelegates.length - 1];
-                allDelegates.length = allDelegates.length - 1;
+                allDelegates[i] = allDelegates[delegateLen - 1];
+                allDelegates.length--;
             }
         }
         delete delegateDetails[_delegate];
@@ -107,17 +108,16 @@ contract GeneralPermissionManager is GeneralPermissionManagerStorage, IPermissio
      */
     function changePermissionMulti(
         address _delegate,
-        address[] calldata _modules,
-        bytes32[] calldata _perms,
-        bool[] calldata _valids
+        address[] memory _modules,
+        bytes32[] memory _perms,
+        bool[] memory _valids
     )
-        external
+        public
         withPerm(ADMIN)
     {
         require(_delegate != address(0), "invalid address");
         require(_modules.length > 0, "0 length is not allowed");
-        require(_modules.length == _perms.length, "Array length mismatch");
-        require(_valids.length == _perms.length, "Array length mismatch");
+        require(_modules.length == _perms.length && _valids.length == _perms.length, "Array length mismatch");
         for (uint256 i = 0; i < _perms.length; i++) {
             _changePermission(_delegate, _modules[i], _perms[i], _valids[i]);
         }
diff --git a/contracts/modules/STO/USDTiered/USDTieredSTO.sol b/contracts/modules/STO/USDTiered/USDTieredSTO.sol
index 6a724270d..67b2fc6f1 100644
--- a/contracts/modules/STO/USDTiered/USDTieredSTO.sol
+++ b/contracts/modules/STO/USDTiered/USDTieredSTO.sol
@@ -1,8 +1,8 @@
 pragma solidity ^0.5.0;
 
 import "../STO.sol";
+import "../../../interfaces/IPolymathRegistry.sol";
 import "../../../interfaces/IOracle.sol";
-import "../../../RegistryUpdater.sol";
 import "../../../libraries/DecimalMath.sol";
 import "openzeppelin-solidity/contracts/math/SafeMath.sol";
 import "./USDTieredSTOStorage.sol";
@@ -758,7 +758,7 @@ contract USDTieredSTO is USDTieredSTOStorage, STO {
     }
 
     function _getOracle(bytes32 _currency, bytes32 _denominatedCurrency) internal view returns(address) {
-        return PolymathRegistry(RegistryUpdater(securityToken).polymathRegistry()).getAddress(oracleKeys[_currency][_denominatedCurrency]);
+        return IPolymathRegistry(ISecurityToken(securityToken).polymathRegistry()).getAddress(oracleKeys[_currency][_denominatedCurrency]);
     }
 
 }
diff --git a/contracts/modules/TransferManager/CTM/CountTransferManager.sol b/contracts/modules/TransferManager/CTM/CountTransferManager.sol
index b32a82ecd..ab3e3d743 100644
--- a/contracts/modules/TransferManager/CTM/CountTransferManager.sol
+++ b/contracts/modules/TransferManager/CTM/CountTransferManager.sol
@@ -28,12 +28,12 @@ contract CountTransferManager is CountTransferManagerStorage, TransferManager {
         address _from,
         address _to,
         uint256 _amount,
-        bytes calldata _data
+        bytes calldata /*_data*/
     )
         external
         returns(Result)
     {
-        (Result success,) = verifyTransfer(_from, _to, _amount, _data);
+        (Result success, ) = _verifyTransfer(_from, _to, _amount);
         return success;
     }
 
@@ -52,6 +52,18 @@ contract CountTransferManager is CountTransferManagerStorage, TransferManager {
         public
         view
         returns(Result, bytes32)
+    {
+        return _verifyTransfer(_from, _to, _amount);
+    }
+
+    function _verifyTransfer(
+        address _from,
+        address _to,
+        uint256 _amount
+    )
+        internal
+        view
+        returns(Result, bytes32)
     {
         if (!paused) {
             if (maxHolderCount < ISecurityToken(securityToken).holderCount()) {
diff --git a/contracts/modules/TransferManager/GTM/GeneralTransferManager.sol b/contracts/modules/TransferManager/GTM/GeneralTransferManager.sol
index 952b518f8..874e47263 100644
--- a/contracts/modules/TransferManager/GTM/GeneralTransferManager.sol
+++ b/contracts/modules/TransferManager/GTM/GeneralTransferManager.sol
@@ -40,7 +40,7 @@ contract GeneralTransferManager is GeneralTransferManagerStorage, TransferManage
     );
 
     event ModifyTransferRequirements(
-        uint256 indexed _transferType,
+        TransferType indexed _transferType,
         bool _fromValidKYC,
         bool _toValidKYC,
         bool _fromRestricted,
@@ -102,7 +102,7 @@ contract GeneralTransferManager is GeneralTransferManagerStorage, TransferManage
     function executeTransfer(
         address _from,
         address _to,
-        uint256 _amount,
+        uint256 /*_amount*/,
         bytes calldata _data
     ) external returns(Result) {
         if (_data.length > 32) {
@@ -115,7 +115,7 @@ contract GeneralTransferManager is GeneralTransferManagerStorage, TransferManage
             if (target == address(this))
                 _processTransferSignature(nonce, validFrom, validTo, data);
         }
-        (Result success,) = verifyTransfer(_from, _to, _amount, _data);
+        (Result success,) = _verifyTransfer(_from, _to);
         return success;
     }
 
@@ -144,6 +144,17 @@ contract GeneralTransferManager is GeneralTransferManagerStorage, TransferManage
         public
         view
         returns(Result, bytes32)
+    {
+        return _verifyTransfer(_from, _to);
+    }
+
+    function _verifyTransfer(
+        address _from,
+        address _to
+    )
+        internal
+        view
+        returns(Result, bytes32)
     {
         if (!paused) {
             TransferRequirements memory txReq;
@@ -153,11 +164,11 @@ contract GeneralTransferManager is GeneralTransferManagerStorage, TransferManage
             uint64 canReceiveAfter;
 
             if (_from == issuanceAddress) {
-                txReq = transferRequirements[1]; //Issuance
+                txReq = transferRequirements[uint8(TransferType.ISSUANCE)];
             } else if (_to == address(0)) {
-                txReq = transferRequirements[2]; //Redemption
+                txReq = transferRequirements[uint8(TransferType.REDEMPTION)];
             } else {
-                txReq = transferRequirements[0]; //General Transfer
+                txReq = transferRequirements[uint8(TransferType.GENERAL)];
             }
 
             (canSendAfter, fromExpiry, canReceiveAfter, toExpiry) = _getValuesForTransfer(_from, _to);
@@ -186,7 +197,7 @@ contract GeneralTransferManager is GeneralTransferManagerStorage, TransferManage
     * @param _toRestricted Defines if transfer time restriction is checked for the receiver
     */
     function modifyTransferRequirements(
-        uint256 _transferType,
+        TransferType _transferType,
         bool _fromValidKYC,
         bool _toValidKYC,
         bool _fromRestricted,
@@ -210,7 +221,7 @@ contract GeneralTransferManager is GeneralTransferManagerStorage, TransferManage
     * @param _toRestricted Defines if transfer time restriction is checked for the receiver
     */
     function modifyTransferRequirementsMulti(
-        uint256[] memory _transferTypes,
+        TransferType[] memory _transferTypes,
         bool[] memory _fromValidKYC,
         bool[] memory _toValidKYC,
         bool[] memory _fromRestricted,
@@ -236,14 +247,13 @@ contract GeneralTransferManager is GeneralTransferManagerStorage, TransferManage
     }
 
     function _modifyTransferRequirements(
-        uint256 _transferType,
+        TransferType _transferType,
         bool _fromValidKYC,
         bool _toValidKYC,
         bool _fromRestricted,
         bool _toRestricted
     ) internal {
-        require(_transferType < 3, "Invalid TransferType");
-        transferRequirements[_transferType] =
+        transferRequirements[uint8(_transferType)] =
             TransferRequirements(
                 _fromValidKYC,
                 _toValidKYC,
@@ -342,7 +352,7 @@ contract GeneralTransferManager is GeneralTransferManagerStorage, TransferManage
         IDataStore dataStore = getDataStore();
         if (!_isExistingInvestor(_investor, dataStore)) {
            dataStore.insertAddress(INVESTORSKEY, _investor);
-           //KYC data can not be present if added is false and hence we can set packed KYC as uint256(1) to set added as true
+           //KYC data can not be present if _isExistingInvestor is false and hence we can set packed KYC as uint256(1) to set `added` as true
            dataStore.setUint256(_getKey(WHITELIST, _investor), uint256(1));
         }
         //NB Flags are packed together in a uint256 to save gas. We can have a maximum of 256 flags.
@@ -500,13 +510,11 @@ contract GeneralTransferManager is GeneralTransferManagerStorage, TransferManage
 
         if (_checkSig(hash, _signature, _nonce)) {
             for (uint256 i = 0; i < _investor.length; i++) {
-                require(
-                    uint64(_canSendAfter[i]) == _canSendAfter[i] &&
+                if (uint64(_canSendAfter[i]) == _canSendAfter[i] &&
                     uint64(_canReceiveAfter[i]) == _canReceiveAfter[i] &&
-                    uint64(_expiryTime[i]) == _expiryTime[i],
-                    "uint64 overflow"
-                );
-                _modifyKYCData(_investor[i], uint64(_canSendAfter[i]), uint64(_canReceiveAfter[i]), uint64(_expiryTime[i]));
+                    uint64(_expiryTime[i]) == _expiryTime[i]
+                )
+                    _modifyKYCData(_investor[i], uint64(_canSendAfter[i]), uint64(_canReceiveAfter[i]), uint64(_expiryTime[i]));
             }
             return true;
         }
diff --git a/contracts/modules/TransferManager/GTM/GeneralTransferManagerProxy.sol b/contracts/modules/TransferManager/GTM/GeneralTransferManagerProxy.sol
index 417c63766..fd44b9fbf 100644
--- a/contracts/modules/TransferManager/GTM/GeneralTransferManagerProxy.sol
+++ b/contracts/modules/TransferManager/GTM/GeneralTransferManagerProxy.sol
@@ -26,9 +26,9 @@ contract GeneralTransferManagerProxy is GeneralTransferManagerStorage, ModuleSto
     {
         require(_implementation != address(0), "Implementation address should not be 0x");
         _upgradeTo(_version, _implementation);
-        transferRequirements[0] = TransferRequirements(true, true, true, true);
-        transferRequirements[1] = TransferRequirements(false, true, false, false);
-        transferRequirements[2] = TransferRequirements(true, false, false, false);
+        transferRequirements[uint8(TransferType.GENERAL)] = TransferRequirements(true, true, true, true);
+        transferRequirements[uint8(TransferType.ISSUANCE)] = TransferRequirements(false, true, false, false);
+        transferRequirements[uint8(TransferType.REDEMPTION)] = TransferRequirements(true, false, false, false);
     }
 
 }
diff --git a/contracts/modules/TransferManager/GTM/GeneralTransferManagerStorage.sol b/contracts/modules/TransferManager/GTM/GeneralTransferManagerStorage.sol
index 1f1d6a07d..4e61eb75f 100644
--- a/contracts/modules/TransferManager/GTM/GeneralTransferManagerStorage.sol
+++ b/contracts/modules/TransferManager/GTM/GeneralTransferManagerStorage.sol
@@ -10,6 +10,8 @@ contract GeneralTransferManagerStorage {
     bytes32 public constant INVESTORFLAGS = "INVESTORFLAGS";
     uint256 internal constant ONE = uint256(1);
 
+    enum TransferType { GENERAL, ISSUANCE, REDEMPTION }
+
     //Address from which issuances come
     address public issuanceAddress;
 
@@ -32,6 +34,6 @@ contract GeneralTransferManagerStorage {
         bool toRestricted;
     }
 
-    mapping(uint256 => TransferRequirements) public transferRequirements;
+    mapping(uint8 => TransferRequirements) public transferRequirements;
     // General = 0, Issuance = 1, Redemption = 2
 }
diff --git a/contracts/modules/TransferManager/MATM/ManualApprovalTransferManager.sol b/contracts/modules/TransferManager/MATM/ManualApprovalTransferManager.sol
index cc16b5046..1d44d6d6a 100644
--- a/contracts/modules/TransferManager/MATM/ManualApprovalTransferManager.sol
+++ b/contracts/modules/TransferManager/MATM/ManualApprovalTransferManager.sol
@@ -59,14 +59,14 @@ contract ManualApprovalTransferManager is ManualApprovalTransferManagerStorage,
         address _from,
         address _to,
         uint256 _amount,
-        bytes calldata _data
+        bytes calldata /* _data */
     )
         external
         onlySecurityToken
         returns(Result)
     {
 
-       (Result success, bytes32 esc) = verifyTransfer(_from, _to, _amount, _data);
+        (Result success, bytes32 esc) = _verifyTransfer(_from, _to, _amount);
         if (esc != bytes32(0)) {
             uint256 index = approvalIndex[_from][_to] - 1;
             ManualApproval storage approval = approvals[index];
@@ -91,6 +91,18 @@ contract ManualApprovalTransferManager is ManualApprovalTransferManagerStorage,
         public
         view
         returns(Result, bytes32)
+    {
+        return _verifyTransfer(_from, _to, _amount);
+    }
+
+    function _verifyTransfer(
+        address _from,
+        address _to,
+        uint256 _amount
+    )
+        internal
+        view
+        returns(Result, bytes32)
     {
         uint256 index = approvalIndex[_from][_to];
         if (!paused && index != 0) {
@@ -147,13 +159,13 @@ contract ManualApprovalTransferManager is ManualApprovalTransferManagerStorage,
     * @param _descriptions is the description array for these manual approvals
     */
     function addManualApprovalMulti(
-        address[] calldata _from,
-        address[] calldata _to,
-        uint256[] calldata _allowances,
-        uint256[] calldata _expiryTimes,
-        bytes32[] calldata _descriptions
+        address[] memory _from,
+        address[] memory _to,
+        uint256[] memory _allowances,
+        uint256[] memory _expiryTimes,
+        bytes32[] memory _descriptions
     )
-        external
+        public
         withPerm(ADMIN)
     {
         _checkInputLengthArray(_from, _to, _allowances, _expiryTimes, _descriptions);
diff --git a/contracts/modules/TransferManager/PTM/PercentageTransferManager.sol b/contracts/modules/TransferManager/PTM/PercentageTransferManager.sol
index 34afae73c..5f3971b11 100644
--- a/contracts/modules/TransferManager/PTM/PercentageTransferManager.sol
+++ b/contracts/modules/TransferManager/PTM/PercentageTransferManager.sol
@@ -41,12 +41,12 @@ contract PercentageTransferManager is PercentageTransferManagerStorage, Transfer
         address _from,
         address _to,
         uint256 _amount,
-        bytes calldata _data
+        bytes calldata /* _data */
     )
         external
         returns(Result)
     {
-        (Result success,) = verifyTransfer(_from, _to, _amount, _data);
+        (Result success,) = _verifyTransfer(_from, _to, _amount);
         return success;
     }
 
@@ -65,6 +65,18 @@ contract PercentageTransferManager is PercentageTransferManagerStorage, Transfer
         public
         view
         returns(Result, bytes32)
+    {
+        return _verifyTransfer(_from, _to, _amount);
+    }
+
+    function _verifyTransfer(
+        address _from,
+        address _to,
+        uint256 _amount
+    )
+        internal
+        view
+        returns(Result, bytes32)
     {
         if (!paused) {
             if (_from == address(0) && allowPrimaryIssuance) {
diff --git a/contracts/modules/TransferManager/VRTM/VolumeRestrictionTM.sol b/contracts/modules/TransferManager/VRTM/VolumeRestrictionTM.sol
index 43d3aa164..12bef17d8 100644
--- a/contracts/modules/TransferManager/VRTM/VolumeRestrictionTM.sol
+++ b/contracts/modules/TransferManager/VRTM/VolumeRestrictionTM.sol
@@ -450,6 +450,10 @@ contract VolumeRestrictionTM is VolumeRestrictionTMStorage, TransferManager {
      * @param _holder Address of the user
      */
     function removeIndividualRestriction(address _holder) public withPerm(ADMIN) {
+        _removeIndividualRestriction(_holder);
+    }
+
+    function _removeIndividualRestriction(address _holder) internal {
         require(_holder != address(0));
         require(individualRestrictions.individualRestriction[_holder].endTime != 0);
         individualRestrictions.individualRestriction[_holder] = VolumeRestriction(0, 0, 0, 0, RestrictionType(0));
@@ -464,9 +468,9 @@ contract VolumeRestrictionTM is VolumeRestrictionTMStorage, TransferManager {
      * @notice use to remove the individual restriction for a given address
      * @param _holders Array of address of the user
      */
-    function removeIndividualRestrictionMulti(address[] calldata _holders) external {
+    function removeIndividualRestrictionMulti(address[] memory _holders) public withPerm(ADMIN) {
         for (uint256 i = 0; i < _holders.length; i++) {
-            removeIndividualRestriction(_holders[i]);
+            _removeIndividualRestriction(_holders[i]);
         }
     }
 
@@ -475,6 +479,10 @@ contract VolumeRestrictionTM is VolumeRestrictionTMStorage, TransferManager {
      * @param _holder Address of the user
      */
     function removeIndividualDailyRestriction(address _holder) public withPerm(ADMIN) {
+        _removeIndividualDailyRestriction(_holder);
+    }
+
+    function _removeIndividualDailyRestriction(address _holder) internal {
         require(_holder != address(0));
         require(individualRestrictions.individualDailyRestriction[_holder].endTime != 0);
         individualRestrictions.individualDailyRestriction[_holder] = VolumeRestriction(0, 0, 0, 0, RestrictionType(0));
@@ -487,9 +495,9 @@ contract VolumeRestrictionTM is VolumeRestrictionTMStorage, TransferManager {
      * @notice use to remove the individual daily restriction for a given address
      * @param _holders Array of address of the user
      */
-    function removeIndividualDailyRestrictionMulti(address[] calldata _holders) external {
+    function removeIndividualDailyRestrictionMulti(address[] memory _holders) public withPerm(ADMIN) {
         for (uint256 i = 0; i < _holders.length; i++) {
-            removeIndividualDailyRestriction(_holders[i]);
+            _removeIndividualDailyRestriction(_holders[i]);
         }
     }
 
@@ -664,7 +672,7 @@ contract VolumeRestrictionTM is VolumeRestrictionTMStorage, TransferManager {
      * @param _rollingPeriodInDays Rolling period in days (Minimum value should be 1 day)
      * @param _endTime Unix timestamp at which restriction effects will gets end.
      * @param _restrictionType Whether it will be `Fixed` (fixed no. of tokens allowed to transact)
-     * or `Percentage` (tokens are calculated as per the totalSupply in the fly). 
+     * or `Percentage` (tokens are calculated as per the totalSupply in the fly).
      */
     function modifyDefaultRestriction(
         uint256 _allowedTokens,
@@ -703,7 +711,7 @@ contract VolumeRestrictionTM is VolumeRestrictionTMStorage, TransferManager {
      * @param _startTime Unix timestamp at which restriction get into effect
      * @param _endTime Unix timestamp at which restriction effects will gets end.
      * @param _restrictionType Whether it will be `Fixed` (fixed no. of tokens allowed to transact)
-     * or `Percentage` (tokens are calculated as per the totalSupply in the fly). 
+     * or `Percentage` (tokens are calculated as per the totalSupply in the fly).
      */
     function modifyDefaultDailyRestriction(
         uint256 _allowedTokens,
@@ -748,7 +756,7 @@ contract VolumeRestrictionTM is VolumeRestrictionTMStorage, TransferManager {
         VolumeRestriction memory _restriction
     )
         internal
-        view 
+        view
         returns (
         Result success,
         uint256 fromTimestamp,
@@ -781,7 +789,7 @@ contract VolumeRestrictionTM is VolumeRestrictionTMStorage, TransferManager {
                 _isDefault,
                 fromTimestamp,
                 BokkyPooBahsDateTimeLibrary.diffDays(fromTimestamp, now),
-                
+
                 daysCovered,
                 _bucketDetails
             );
@@ -793,7 +801,7 @@ contract VolumeRestrictionTM is VolumeRestrictionTMStorage, TransferManager {
                 allowedDefault = false;
             }
         }
-        
+
         // reusing the local variable to avoid stack too deep error
         // here variable endTime is representing the allowedDailyAmount
         (allowedDaily, dailyTime, endTime) = _dailyTxCheck(_amount, _from, _isDefault, _bucketDetails.dailyLastTradedDayTime, dailyRestriction);
@@ -811,13 +819,13 @@ contract VolumeRestrictionTM is VolumeRestrictionTMStorage, TransferManager {
     )
         internal
         view
-        returns (uint256) 
-    {   
+        returns (uint256)
+    {
         if (now > dailyRestriction.endTime || now < dailyRestriction.startTime)
             return allowedAmount;
         else if (now > restriction.endTime || now < restriction.startTime)
             return allowedDailyAmount;
-        else 
+        else
             return Math.min(allowedDailyAmount, allowedAmount);
     }
 
@@ -826,7 +834,7 @@ contract VolumeRestrictionTM is VolumeRestrictionTMStorage, TransferManager {
      * default to individual or vice versa. It will return true when last transaction traded by the user
      * and the current txn timestamp lies in the same day.
      * NB - Instead of comparing the current day transaction amount, we are comparing the total amount traded
-     * on the lastTradedDayTime that makes the restriction strict. The reason is not availability of amount 
+     * on the lastTradedDayTime that makes the restriction strict. The reason is not availability of amount
      * that transacted on the current day (because of bucket desgin).
      */
     function _isValidAmountAfterRestrictionChanges(
@@ -877,7 +885,7 @@ contract VolumeRestrictionTM is VolumeRestrictionTMStorage, TransferManager {
                 txSumOfDay = bucketData.defaultBucket[_from][_dailyLastTradedDayTime];
             else
                 txSumOfDay = bucketData.bucket[_from][_dailyLastTradedDayTime];
-            (bool isAllowed, uint256 allowedAmount) = _checkValidAmountToTransact(_amount, _from, _isDefault, _restriction, txSumOfDay); 
+            (bool isAllowed, uint256 allowedAmount) = _checkValidAmountToTransact(_amount, _from, _isDefault, _restriction, txSumOfDay);
             return (isAllowed, _dailyLastTradedDayTime, allowedAmount);
         }
         return (true, _dailyLastTradedDayTime, _amount);
@@ -1088,7 +1096,7 @@ contract VolumeRestrictionTM is VolumeRestrictionTMStorage, TransferManager {
         uint256 currentBalance = (msg.sender == securityToken) ? (IERC20(securityToken).balanceOf(_tokenHolder)).add(_additionalBalance) : IERC20(securityToken).balanceOf(_tokenHolder);
         if (paused)
             return (_partition == UNLOCKED ? currentBalance: 0);
-        
+
         (,fromTimestamp,,,dailyTime,,allowedAmountToTransact,) = _verifyTransfer(_tokenHolder, 0);
         if (_partition == LOCKED) {
             if (allowedAmountToTransact == 0 && fromTimestamp == 0 && dailyTime == 0)
diff --git a/contracts/storage/EternalStorage.sol b/contracts/storage/EternalStorage.sol
index 40175f31d..a3b914b60 100644
--- a/contracts/storage/EternalStorage.sol
+++ b/contracts/storage/EternalStorage.sol
@@ -56,6 +56,10 @@ contract EternalStorage {
         stringStorage[_key] = _value;
     }
 
+    function set(bytes32 _key, bytes memory _value) internal {
+        bytesStorage[_key] = _value;
+    }
+
     ////////////////////////////
     // deleteArray functions
     ////////////////////////////
diff --git a/contracts/tokens/SecurityToken.sol b/contracts/tokens/SecurityToken.sol
index b432f33de..65ab132d9 100644
--- a/contracts/tokens/SecurityToken.sol
+++ b/contracts/tokens/SecurityToken.sol
@@ -53,14 +53,6 @@ contract SecurityToken is ERC20, ReentrancyGuard, SecurityTokenStorage, IERC1594
     event FreezeIssuance();
     // Emit when transfers are frozen or unfrozen
     event FreezeTransfers(bool _status);
-    // Emit when Module get archived from the securityToken
-    event ModuleArchived(uint8[] _types, address _module);
-    // Emit when Module get unarchived from the securityToken
-    event ModuleUnarchived(uint8[] _types, address _module);
-    // Emit when Module get removed from the securityToken
-    event ModuleRemoved(uint8[] _types, address _module);
-    // Emit when the budget allocated to a module is changed
-    event ModuleBudgetChanged(uint8[] _moduleTypes, address _module, uint256 _oldBudget, uint256 _budget);
     // Emit when new checkpoint created
     event CheckpointCreated(uint256 indexed _checkpointId, uint256 _investorLength);
     // Events to log controller actions
@@ -71,6 +63,15 @@ contract SecurityToken is ERC20, ReentrancyGuard, SecurityTokenStorage, IERC1594
     event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
     event TokenUpgraded(uint8 _major, uint8 _minor, uint8 _patch);
 
+    // Emit when Module get archived from the securityToken
+    event ModuleArchived(uint8[] _types, address _module); //Event emitted by the tokenLib.
+    // Emit when Module get unarchived from the securityToken
+    event ModuleUnarchived(uint8[] _types, address _module); //Event emitted by the tokenLib.
+    // Emit when Module get removed from the securityToken
+    event ModuleRemoved(uint8[] _types, address _module); //Event emitted by the tokenLib.
+    // Emit when the budget allocated to a module is changed
+    event ModuleBudgetChanged(uint8[] _moduleTypes, address _module, uint256 _oldBudget, uint256 _budget); //Event emitted by the tokenLib.
+
     /**
      * @notice Initialization function
      * @dev Expected to be called atomically with the proxy being created, by the owner of the token
@@ -213,7 +214,15 @@ contract SecurityToken is ERC20, ReentrancyGuard, SecurityTokenStorage, IERC1594
         _addModuleData(moduleTypes, _moduleFactory, module, moduleCost, _budget, _label, _archived);
     }
 
-    function _addModuleData(uint8[] memory _moduleTypes, address _moduleFactory, address _module, uint256 _moduleCost, uint256 _budget, bytes32 _label, bool _archived) internal {
+    function _addModuleData(
+        uint8[] memory _moduleTypes,
+        address _moduleFactory,
+        address _module,
+        uint256 _moduleCost,
+        uint256 _budget,
+        bytes32 _label,
+        bool _archived
+    ) internal {
         bytes32 moduleName = IModuleFactory(_moduleFactory).name();
         uint256[] memory moduleIndexes = new uint256[](_moduleTypes.length);
         uint256 i;
@@ -265,6 +274,10 @@ contract SecurityToken is ERC20, ReentrancyGuard, SecurityTokenStorage, IERC1594
     */
     function upgradeToken() external {
         _onlyOwner();
+        // 10 is the number of module types to check for incompatibilities before upgrading.
+        // The number is hard coded and kept low to keep usage low.
+        // We currently have 7 module types. If we ever create more than 3 new module types,
+        // We will upgrade the implementation accordinly. We understand the limitations of this approach.
         IUpgradableTokenFactory(tokenFactory).upgradeToken(10);
         emit TokenUpgraded(securityTokenVersion.major, securityTokenVersion.minor, securityTokenVersion.patch);
     }
@@ -430,7 +443,7 @@ contract SecurityToken is ERC20, ReentrancyGuard, SecurityTokenStorage, IERC1594
 
     function _transferWithData(address _from, address _to, uint256 _value, bytes memory _data) internal {
         _isValidTransfer(_updateTransfer(_from, _to, _value, _data));
-        // Using the internal function instead of super.transfer() in the favour of reducing the code size 
+        // Using the internal function instead of super.transfer() in the favour of reducing the code size
         _transfer(_from, _to, _value);
     }
 
@@ -505,12 +518,12 @@ contract SecurityToken is ERC20, ReentrancyGuard, SecurityTokenStorage, IERC1594
         bytes memory _data,
         address _operator,
         bytes memory _operatorData
-    ) 
+    )
         internal
-        returns(bytes32 toPartition) 
+        returns(bytes32 toPartition)
     {
         _isValidPartition(_partition);
-        // Avoiding to add this check 
+        // Avoiding to add this check
         // require(balanceOfByPartition(_partition, msg.sender) >= _value);
         // NB - Above condition will be automatically checked using the executeTransfer() function execution.
         // NB - passing `_additionalBalance` value is 0 because accessing the balance before transfer
@@ -527,21 +540,21 @@ contract SecurityToken is ERC20, ReentrancyGuard, SecurityTokenStorage, IERC1594
         // balance otherwise return UNLOCKED
         if (_afterBalance.sub(_beforeBalance) == _value)
             toPartition = LOCKED;
-        // Returning the same partition UNLOCKED 
+        // Returning the same partition UNLOCKED
         toPartition = UNLOCKED;
     }
 
     ///////////////////////
     /// Operator Management
     ///////////////////////
-    
+
     /**
      * @notice Authorises an operator for all partitions of `msg.sender`.
      * NB - Allowing investors to authorize an investor to be an operator of all partitions
      * but it doesn't mean we operator is allowed to transfer the LOCKED partition values.
      * Logic for this restriction is written in `operatorTransferByPartition()` function.
      * @param _operator An address which is being authorised.
-     */ 
+     */
     function authorizeOperator(address _operator) public {
         _approve(msg.sender, _operator, uint(-1));
         emit AuthorizedOperator(_operator, msg.sender);
@@ -598,9 +611,9 @@ contract SecurityToken is ERC20, ReentrancyGuard, SecurityTokenStorage, IERC1594
         uint256 _value,
         bytes calldata _data,
         bytes calldata _operatorData
-    ) 
+    )
         external
-        returns (bytes32) 
+        returns (bytes32)
     {
         // For the current release we are only allowing UNLOCKED partition tokens to transact
         _validateOperatorAndPartition(_partition, _from, msg.sender);
@@ -628,7 +641,7 @@ contract SecurityToken is ERC20, ReentrancyGuard, SecurityTokenStorage, IERC1594
         //  - checkpoints are updated after the transfer managers are called. This allows TMs to create
         //checkpoints as though they have been created before the current transactions,
         //  - to avoid the situation where a transfer manager transfers tokens, and this function is called recursively,
-        //the function is marked as nonReentrant. This means that no TM can transfer (or mint / burn) tokens.
+        //the function is marked as nonReentrant. This means that no TM can transfer (or mint / burn) tokens in the execute transfer function.
         _adjustInvestorCount(_from, _to, _value);
         verified = _executeTransfer(_from, _to, _value, _data);
         _adjustBalanceCheckpoints(_from);
@@ -709,7 +722,7 @@ contract SecurityToken is ERC20, ReentrancyGuard, SecurityTokenStorage, IERC1594
         uint256 _value,
         bytes memory _data
     )
-        public // changed to public to save the code size and reuse the function 
+        public // changed to public to save the code size and reuse the function
     {
         _isIssuanceAllowed();
         _onlyModuleOrOwner(MINT_KEY);
@@ -736,10 +749,10 @@ contract SecurityToken is ERC20, ReentrancyGuard, SecurityTokenStorage, IERC1594
      * @param _values A list of number of tokens get minted and transfer to corresponding address of the investor from _tokenHolders[] list
      * @return success
      */
-    function issueMulti(address[] calldata _tokenHolders, uint256[] calldata _values) external {
+    function issueMulti(address[] memory _tokenHolders, uint256[] memory _values) public {
         _isIssuanceAllowed();
         _onlyModuleOrOwner(MINT_KEY);
-        // Remove reason string to reduce the code size 
+        // Remove reason string to reduce the code size
         require(_tokenHolders.length == _values.length);
         for (uint256 i = 0; i < _tokenHolders.length; i++) {
             _issue(_tokenHolders[i], _values[i], "");
@@ -796,8 +809,8 @@ contract SecurityToken is ERC20, ReentrancyGuard, SecurityTokenStorage, IERC1594
         address _operator,
         bytes memory _data,
         bytes memory _operatorData
-    )   
-        internal 
+    )
+        internal
     {
         _redeem(_from, _value, _data);
         emit RedeemedByPartition(_partition, _operator, _from, _value, _data, _operatorData);
@@ -818,10 +831,10 @@ contract SecurityToken is ERC20, ReentrancyGuard, SecurityTokenStorage, IERC1594
         uint256 _value,
         bytes calldata _data,
         bytes calldata _operatorData
-    ) 
+    )
         external
     {
-        _onlyModule(BURN_KEY); 
+        _onlyModule(BURN_KEY);
         require(_operatorData[0] != 0);
         _zeroAddressCheck(_tokenHolder);
         _validateOperatorAndPartition(_partition, _tokenHolder, msg.sender);
@@ -932,7 +945,7 @@ contract SecurityToken is ERC20, ReentrancyGuard, SecurityTokenStorage, IERC1594
             return (false, 0x50, bytes32(0));
         }
         (success, appCode) = TokenLib.verifyTransfer(modules[TRANSFER_KEY], modulesToData, _from, _to, _value, _data, transfersFrozen);
-        return TokenLib.canTransfer(success, appCode, _to, _value, balanceOf(_from), balanceOf(_to));
+        return TokenLib.canTransfer(success, appCode, _to, _value, balanceOf(_from));
     }
 
     /**
@@ -957,7 +970,7 @@ contract SecurityToken is ERC20, ReentrancyGuard, SecurityTokenStorage, IERC1594
         external
         view
         returns (byte esc, bytes32 appStatusCode, bytes32 toPartition)
-    {   
+    {
         if (_partition == UNLOCKED) {
             bool success;
             (success, esc, appStatusCode) = _canTransfer(_from, _to, _value, _data);
@@ -968,7 +981,7 @@ contract SecurityToken is ERC20, ReentrancyGuard, SecurityTokenStorage, IERC1594
             }
             return (esc, appStatusCode, toPartition);
         }
-        return (0x50, bytes32(0), bytes32(0));   
+        return (0x50, bytes32(0), bytes32(0));
     }
 
     /**