diff --git a/liblangutil/Exceptions.cpp b/liblangutil/Exceptions.cpp
index 2595c7755..92fe2589a 100644
--- a/liblangutil/Exceptions.cpp
+++ b/liblangutil/Exceptions.cpp
@@ -39,34 +39,6 @@ Error::Error(
 	m_errorId(_errorId),
 	m_type(_type)
 {
-	switch (m_type)
-	{
-	case Type::CodeGenerationError:
-		m_typeName = "CodeGenerationError";
-		break;
-	case Type::DeclarationError:
-		m_typeName = "DeclarationError";
-		break;
-	case Type::DocstringParsingError:
-		m_typeName = "DocstringParsingError";
-		break;
-	case Type::Info:
-		m_typeName = "Info";
-		break;
-	case Type::ParserError:
-		m_typeName = "ParserError";
-		break;
-	case Type::SyntaxError:
-		m_typeName = "SyntaxError";
-		break;
-	case Type::TypeError:
-		m_typeName = "TypeError";
-		break;
-	case Type::Warning:
-		m_typeName = "Warning";
-		break;
-	}
-
 	if (_location.isValid())
 		*this << errinfo_sourceLocation(_location);
 	if (!_secondaryLocation.infos.empty())
@@ -84,15 +56,3 @@ SecondarySourceLocation const* Error::secondarySourceLocation() const noexcept
 {
 	return boost::get_error_info<errinfo_secondarySourceLocation>(*this);
 }
-
-optional<Error::Severity> Error::severityFromString(string _input)
-{
-	boost::algorithm::to_lower(_input);
-	boost::algorithm::trim(_input);
-
-	for (Severity severity: {Severity::Error, Severity::Warning, Severity::Info})
-		if (_input == formatErrorSeverityLowercase(severity))
-			return severity;
-
-	return nullopt;
-}
diff --git a/liblangutil/Exceptions.h b/liblangutil/Exceptions.h
index fb6f23cf1..fc7286ed1 100644
--- a/liblangutil/Exceptions.h
+++ b/liblangutil/Exceptions.h
@@ -31,11 +31,13 @@
 #include <boost/preprocessor/cat.hpp>
 #include <boost/preprocessor/facilities/empty.hpp>
 #include <boost/preprocessor/facilities/overload.hpp>
+#include <boost/algorithm/string/case_conv.hpp>
 
 #include <string>
 #include <utility>
 #include <vector>
 #include <memory>
+#include <variant>
 
 namespace solidity::langutil
 {
@@ -174,6 +176,15 @@ public:
 		ParserError,
 		TypeError,
 		SyntaxError,
+		IOError,
+		FatalError,
+		JSONError,
+		InternalCompilerError,
+		CompilerError,
+		Exception,
+		UnimplementedFeatureError,
+		YulException,
+		SMTLogicException,
 		Warning,
 		Info
 	};
@@ -195,7 +206,6 @@ public:
 
 	ErrorId errorId() const { return m_errorId; }
 	Type type() const { return m_type; }
-	std::string const& typeName() const { return m_typeName; }
 
 	SourceLocation const* sourceLocation() const noexcept;
 	SecondarySourceLocation const* secondarySourceLocation() const noexcept;
@@ -211,11 +221,19 @@ public:
 
 	static constexpr Severity errorSeverity(Type _type)
 	{
-		if (_type == Type::Info)
-			return Severity::Info;
-		if (_type == Type::Warning)
-			return Severity::Warning;
-		return Severity::Error;
+		switch (_type)
+		{
+			case Type::Info: return Severity::Info;
+			case Type::Warning: return Severity::Warning;
+			default: return Severity::Error;
+		}
+	}
+
+	static constexpr Severity errorSeverityOrType(std::variant<Error::Type, Error::Severity> _typeOrSeverity)
+	{
+		if (std::holds_alternative<Error::Type>(_typeOrSeverity))
+			return errorSeverity(std::get<Error::Type>(_typeOrSeverity));
+		return std::get<Error::Severity>(_typeOrSeverity);
 	}
 
 	static bool isError(Severity _severity)
@@ -238,35 +256,57 @@ public:
 
 	static std::string formatErrorSeverity(Severity _severity)
 	{
-		if (_severity == Severity::Info)
-			return "Info";
-		if (_severity == Severity::Warning)
-			return "Warning";
-		solAssert(isError(_severity), "");
-		return "Error";
+		switch (_severity)
+		{
+		case Severity::Info: return "Info";
+		case Severity::Warning: return "Warning";
+		case Severity::Error: return "Error";
+		}
+		util::unreachable();
+	}
+
+	static std::string formatErrorType(Type _type)
+	{
+		switch (_type)
+		{
+		case Type::IOError: return "IOError";
+		case Type::FatalError: return "FatalError";
+		case Type::JSONError: return "JSONError";
+		case Type::InternalCompilerError: return "InternalCompilerError";
+		case Type::CompilerError: return "CompilerError";
+		case Type::Exception: return "Exception";
+		case Type::CodeGenerationError: return "CodeGenerationError";
+		case Type::DeclarationError: return "DeclarationError";
+		case Type::DocstringParsingError: return "DocstringParsingError";
+		case Type::ParserError: return "ParserError";
+		case Type::SyntaxError: return "SyntaxError";
+		case Type::TypeError: return "TypeError";
+		case Type::UnimplementedFeatureError: return "UnimplementedFeatureError";
+		case Type::YulException: return "YulException";
+		case Type::SMTLogicException: return "SMTLogicException";
+		case Type::Warning: return "Warning";
+		case Type::Info: return "Info";
+		}
+		util::unreachable();
+	}
+
+	static std::string formatTypeOrSeverity(std::variant<Error::Type, Error::Severity> _typeOrSeverity)
+	{
+		if (std::holds_alternative<Error::Type>(_typeOrSeverity))
+			return formatErrorType(std::get<Error::Type>(_typeOrSeverity));
+		return formatErrorSeverity(std::get<Error::Severity>(_typeOrSeverity));
 	}
 
 	static std::string formatErrorSeverityLowercase(Severity _severity)
 	{
-		switch (_severity)
-		{
-		case Severity::Info:
-			return "info";
-		case Severity::Warning:
-			return "warning";
-		case Severity::Error:
-			solAssert(isError(_severity), "");
-			return "error";
-		}
-		solAssert(false, "");
+		std::string severityValue = formatErrorSeverity(_severity);
+		boost::algorithm::to_lower(severityValue);
+		return severityValue;
 	}
 
-	static std::optional<Severity> severityFromString(std::string _input);
-
 private:
 	ErrorId m_errorId;
 	Type m_type;
-	std::string m_typeName;
 };
 
 }
diff --git a/liblangutil/SourceReferenceExtractor.cpp b/liblangutil/SourceReferenceExtractor.cpp
index 373ad6b18..01f22a1f7 100644
--- a/liblangutil/SourceReferenceExtractor.cpp
+++ b/liblangutil/SourceReferenceExtractor.cpp
@@ -22,6 +22,7 @@
 
 #include <algorithm>
 #include <cmath>
+#include <variant>
 
 using namespace std;
 using namespace solidity;
@@ -30,7 +31,7 @@ using namespace solidity::langutil;
 SourceReferenceExtractor::Message SourceReferenceExtractor::extract(
 	CharStreamProvider const& _charStreamProvider,
 	util::Exception const& _exception,
-	string _severity
+	std::variant<Error::Type, Error::Severity> _typeOrSeverity
 )
 {
 	SourceLocation const* location = boost::get_error_info<errinfo_sourceLocation>(_exception);
@@ -44,16 +45,16 @@ SourceReferenceExtractor::Message SourceReferenceExtractor::extract(
 		for (auto const& info: secondaryLocation->infos)
 			secondary.emplace_back(extract(_charStreamProvider, &info.second, info.first));
 
-	return Message{std::move(primary), _severity, std::move(secondary), nullopt};
+	return Message{std::move(primary), _typeOrSeverity, std::move(secondary), nullopt};
 }
 
 SourceReferenceExtractor::Message SourceReferenceExtractor::extract(
 	CharStreamProvider const& _charStreamProvider,
-	Error const& _error
+	Error const& _error,
+	std::variant<Error::Type, Error::Severity> _typeOrSeverity
 )
 {
-	string severity = Error::formatErrorSeverity(Error::errorSeverity(_error.type()));
-	Message message = extract(_charStreamProvider, _error, severity);
+	Message message = extract(_charStreamProvider, static_cast<util::Exception>(_error), _typeOrSeverity);
 	message.errorId = _error.errorId();
 	return message;
 }
diff --git a/liblangutil/SourceReferenceExtractor.h b/liblangutil/SourceReferenceExtractor.h
index 3b418fcfa..3f7751f0b 100644
--- a/liblangutil/SourceReferenceExtractor.h
+++ b/liblangutil/SourceReferenceExtractor.h
@@ -24,6 +24,7 @@
 #include <string>
 #include <tuple>
 #include <vector>
+#include <variant>
 
 namespace solidity::langutil
 {
@@ -55,12 +56,21 @@ namespace SourceReferenceExtractor
 	struct Message
 	{
 		SourceReference primary;
-		std::string severity; // "Error", "Warning", "Info", ...
+		std::variant<Error::Type, Error::Severity> _typeOrSeverity;
 		std::vector<SourceReference> secondary;
 		std::optional<ErrorId> errorId;
 	};
 
-	Message extract(CharStreamProvider const& _charStreamProvider, util::Exception const& _exception, std::string _severity);
+	Message extract(
+		CharStreamProvider const& _charStreamProvider,
+		util::Exception const& _exception,
+		std::variant<Error::Type, Error::Severity> _typeOrSeverity
+	);
+	Message extract(
+		CharStreamProvider const& _charStreamProvider,
+		Error const& _error,
+		std::variant<Error::Type, Error::Severity> _typeOrSeverity
+	);
 	Message extract(CharStreamProvider const& _charStreamProvider, Error const& _error);
 	SourceReference extract(CharStreamProvider const& _charStreamProvider, SourceLocation const* _location, std::string message = "");
 }
diff --git a/liblangutil/SourceReferenceFormatter.cpp b/liblangutil/SourceReferenceFormatter.cpp
index a38c5e617..4765b9fb2 100644
--- a/liblangutil/SourceReferenceFormatter.cpp
+++ b/liblangutil/SourceReferenceFormatter.cpp
@@ -26,6 +26,7 @@
 #include <libsolutil/UTF8.h>
 #include <iomanip>
 #include <string_view>
+#include <variant>
 
 using namespace std;
 using namespace solidity;
@@ -65,19 +66,18 @@ AnsiColorized SourceReferenceFormatter::frameColored() const
 	return AnsiColorized(m_stream, m_colored, {BOLD, BLUE});
 }
 
-AnsiColorized SourceReferenceFormatter::errorColored(optional<Error::Severity> _severity) const
+AnsiColorized SourceReferenceFormatter::errorColored(Error::Severity _severity) const
 {
 	// We used to color messages of any severity as errors so this seems like a good default
 	// for cases where severity cannot be determined.
 	char const* textColor = RED;
 
-	if (_severity.has_value())
-		switch (_severity.value())
-		{
-		case Error::Severity::Error: textColor = RED; break;
-		case Error::Severity::Warning: textColor = YELLOW; break;
-		case Error::Severity::Info: textColor = WHITE; break;
-		}
+	switch (_severity)
+	{
+	case Error::Severity::Error: textColor = RED; break;
+	case Error::Severity::Warning: textColor = YELLOW; break;
+	case Error::Severity::Info: textColor = WHITE; break;
+	}
 
 	return AnsiColorized(m_stream, m_colored, {BOLD, textColor});
 }
@@ -178,13 +178,12 @@ void SourceReferenceFormatter::printSourceLocation(SourceReference const& _ref)
 
 void SourceReferenceFormatter::printExceptionInformation(SourceReferenceExtractor::Message const& _msg)
 {
-	// exception header line
-	optional<Error::Severity> severity = Error::severityFromString(_msg.severity);
-	errorColored(severity) << _msg.severity;
-	if (m_withErrorIds && _msg.errorId.has_value())
-		errorColored(severity) << " (" << _msg.errorId.value().error << ")";
-	messageColored() << ": " << _msg.primary.message << '\n';
+	errorColored(Error::errorSeverityOrType(_msg._typeOrSeverity)) << Error::formatTypeOrSeverity(_msg._typeOrSeverity);
 
+	if (m_withErrorIds && _msg.errorId.has_value())
+		errorColored(Error::errorSeverityOrType(_msg._typeOrSeverity)) << " (" << _msg.errorId.value().error << ")";
+
+	messageColored() << ": " << _msg.primary.message << '\n';
 	printSourceLocation(_msg.primary);
 
 	for (auto const& secondary: _msg.secondary)
@@ -197,7 +196,12 @@ void SourceReferenceFormatter::printExceptionInformation(SourceReferenceExtracto
 	m_stream << '\n';
 }
 
-void SourceReferenceFormatter::printExceptionInformation(util::Exception const& _exception, std::string const& _severity)
+void SourceReferenceFormatter::printExceptionInformation(util::Exception const& _exception, Error::Type _type)
+{
+	printExceptionInformation(SourceReferenceExtractor::extract(m_charStreamProvider, _exception, _type));
+}
+
+void SourceReferenceFormatter::printExceptionInformation(util::Exception const& _exception, Error::Severity _severity)
 {
 	printExceptionInformation(SourceReferenceExtractor::extract(m_charStreamProvider, _exception, _severity));
 }
@@ -210,5 +214,11 @@ void SourceReferenceFormatter::printErrorInformation(ErrorList const& _errors)
 
 void SourceReferenceFormatter::printErrorInformation(Error const& _error)
 {
-	printExceptionInformation(SourceReferenceExtractor::extract(m_charStreamProvider, _error));
+	SourceReferenceExtractor::Message message =
+		SourceReferenceExtractor::extract(
+			m_charStreamProvider,
+			_error,
+			Error::errorSeverity(_error.type())
+		);
+	printExceptionInformation(message);
 }
diff --git a/liblangutil/SourceReferenceFormatter.h b/liblangutil/SourceReferenceFormatter.h
index e18400b60..def216efa 100644
--- a/liblangutil/SourceReferenceFormatter.h
+++ b/liblangutil/SourceReferenceFormatter.h
@@ -52,13 +52,14 @@ public:
 	/// Prints source location if it is given.
 	void printSourceLocation(SourceReference const& _ref);
 	void printExceptionInformation(SourceReferenceExtractor::Message const& _msg);
-	void printExceptionInformation(util::Exception const& _exception, std::string const& _severity);
+	void printExceptionInformation(util::Exception const& _exception, Error::Type _type);
+	void printExceptionInformation(util::Exception const& _exception, Error::Severity _severity);
 	void printErrorInformation(langutil::ErrorList const& _errors);
 	void printErrorInformation(Error const& _error);
 
 	static std::string formatExceptionInformation(
 		util::Exception const& _exception,
-		std::string const& _name,
+		Error::Type _type,
 		CharStreamProvider const& _charStreamProvider,
 		bool _colored = false,
 		bool _withErrorIds = false
@@ -66,7 +67,21 @@ public:
 	{
 		std::ostringstream errorOutput;
 		SourceReferenceFormatter formatter(errorOutput, _charStreamProvider, _colored, _withErrorIds);
-		formatter.printExceptionInformation(_exception, _name);
+		formatter.printExceptionInformation(_exception, _type);
+		return errorOutput.str();
+	}
+
+	static std::string formatExceptionInformation(
+		util::Exception const& _exception,
+		Error::Severity _severity,
+		CharStreamProvider const& _charStreamProvider,
+		bool _colored = false,
+		bool _withErrorIds = false
+	)
+	{
+		std::ostringstream errorOutput;
+		SourceReferenceFormatter formatter(errorOutput, _charStreamProvider, _colored, _withErrorIds);
+		formatter.printExceptionInformation(_exception, _severity);
 		return errorOutput.str();
 	}
 
@@ -77,7 +92,7 @@ public:
 	{
 		return formatExceptionInformation(
 			_error,
-			Error::formatErrorSeverity(Error::errorSeverity(_error.type())),
+			Error::errorSeverity(_error.type()),
 			_charStreamProvider
 		);
 	}
@@ -87,7 +102,7 @@ public:
 private:
 	util::AnsiColorized normalColored() const;
 	util::AnsiColorized frameColored() const;
-	util::AnsiColorized errorColored(std::optional<langutil::Error::Severity> _severity) const;
+	util::AnsiColorized errorColored(langutil::Error::Severity _severity) const;
 	util::AnsiColorized messageColored() const;
 	util::AnsiColorized secondaryColored() const;
 	util::AnsiColorized highlightColored() const;
diff --git a/libsolidity/interface/StandardCompiler.cpp b/libsolidity/interface/StandardCompiler.cpp
index 0af55df16..551bd6af7 100644
--- a/libsolidity/interface/StandardCompiler.cpp
+++ b/libsolidity/interface/StandardCompiler.cpp
@@ -54,8 +54,7 @@ namespace
 {
 
 Json::Value formatError(
-	Error::Severity _severity,
-	string const& _type,
+	Error::Type _type,
 	string const& _component,
 	string const& _message,
 	string const& _formattedMessage = "",
@@ -64,9 +63,9 @@ Json::Value formatError(
 )
 {
 	Json::Value error{Json::objectValue};
-	error["type"] = _type;
+	error["type"] = Error::formatErrorType(_type);
 	error["component"] = _component;
-	error["severity"] = Error::formatErrorSeverityLowercase(_severity);
+	error["severity"] = Error::formatErrorSeverityLowercase(Error::errorSeverity(_type));
 	error["message"] = _message;
 	error["formattedMessage"] = (_formattedMessage.length() > 0) ? _formattedMessage : _message;
 	if (_sourceLocation.isObject())
@@ -76,11 +75,11 @@ Json::Value formatError(
 	return error;
 }
 
-Json::Value formatFatalError(string const& _type, string const& _message)
+Json::Value formatFatalError(Error::Type _type, string const& _message)
 {
 	Json::Value output{Json::objectValue};
 	output["errors"] = Json::arrayValue;
-	output["errors"].append(formatError(Error::Severity::Error, _type, "general", _message));
+	output["errors"].append(formatError(_type, "general", _message));
 	return output;
 }
 
@@ -114,8 +113,7 @@ Json::Value formatSecondarySourceLocation(SecondarySourceLocation const* _second
 Json::Value formatErrorWithException(
 	CharStreamProvider const& _charStreamProvider,
 	util::Exception const& _exception,
-	Error::Severity _severity,
-	string const& _type,
+	Error::Type _type,
 	string const& _component,
 	string const& _message,
 	optional<ErrorId> _errorId = nullopt
@@ -126,7 +124,9 @@ Json::Value formatErrorWithException(
 	string formattedMessage = SourceReferenceFormatter::formatExceptionInformation(
 		_exception,
 		_type,
-		_charStreamProvider
+		_charStreamProvider,
+		false, // colored
+		false // _withErrorIds
 	);
 
 	if (string const* description = _exception.comment())
@@ -135,7 +135,6 @@ Json::Value formatErrorWithException(
 		message = _message;
 
 	Json::Value error = formatError(
-		_severity,
 		_type,
 		_component,
 		message,
@@ -410,11 +409,11 @@ Json::Value collectEVMObject(
 std::optional<Json::Value> checkKeys(Json::Value const& _input, set<string> const& _keys, string const& _name)
 {
 	if (!!_input && !_input.isObject())
-		return formatFatalError("JSONError", "\"" + _name + "\" must be an object");
+		return formatFatalError(Error::Type::JSONError, "\"" + _name + "\" must be an object");
 
 	for (auto const& member: _input.getMemberNames())
 		if (!_keys.count(member))
-			return formatFatalError("JSONError", "Unknown key \"" + member + "\"");
+			return formatFatalError(Error::Type::JSONError, "Unknown key \"" + member + "\"");
 
 	return std::nullopt;
 }
@@ -466,7 +465,7 @@ std::optional<Json::Value> checkOptimizerDetail(Json::Value const& _details, std
 	if (_details.isMember(_name))
 	{
 		if (!_details[_name].isBool())
-			return formatFatalError("JSONError", "\"settings.optimizer.details." + _name + "\" must be Boolean");
+			return formatFatalError(Error::Type::JSONError, "\"settings.optimizer.details." + _name + "\" must be Boolean");
 		_setting = _details[_name].asBool();
 	}
 	return {};
@@ -485,7 +484,7 @@ std::optional<Json::Value> checkOptimizerDetailSteps(Json::Value const& _details
 			catch (yul::OptimizerException const& _exception)
 			{
 				return formatFatalError(
-					"JSONError",
+					Error::Type::JSONError,
 					"Invalid optimizer step sequence in \"settings.optimizer.details." + _name + "\": " + _exception.what()
 				);
 			}
@@ -500,7 +499,7 @@ std::optional<Json::Value> checkOptimizerDetailSteps(Json::Value const& _details
 				solAssert(_cleanupSetting == OptimiserSettings::DefaultYulOptimiserCleanupSteps);
 		}
 		else
-			return formatFatalError("JSONError", "\"settings.optimizer.details." + _name + "\" must be a string");
+			return formatFatalError(Error::Type::JSONError, "\"settings.optimizer.details." + _name + "\" must be a string");
 
 	}
 	return {};
@@ -511,11 +510,11 @@ std::optional<Json::Value> checkMetadataKeys(Json::Value const& _input)
 	if (_input.isObject())
 	{
 		if (_input.isMember("useLiteralContent") && !_input["useLiteralContent"].isBool())
-			return formatFatalError("JSONError", "\"settings.metadata.useLiteralContent\" must be Boolean");
+			return formatFatalError(Error::Type::JSONError, "\"settings.metadata.useLiteralContent\" must be Boolean");
 
 		static set<string> hashes{"ipfs", "bzzr1", "none"};
 		if (_input.isMember("bytecodeHash") && !hashes.count(_input["bytecodeHash"].asString()))
-			return formatFatalError("JSONError", "\"settings.metadata.bytecodeHash\" must be \"ipfs\", \"bzzr1\" or \"none\"");
+			return formatFatalError(Error::Type::JSONError, "\"settings.metadata.bytecodeHash\" must be \"ipfs\", \"bzzr1\" or \"none\"");
 	}
 	static set<string> keys{"useLiteralContent", "bytecodeHash"};
 	return checkKeys(_input, keys, "settings.metadata");
@@ -524,7 +523,7 @@ std::optional<Json::Value> checkMetadataKeys(Json::Value const& _input)
 std::optional<Json::Value> checkOutputSelection(Json::Value const& _outputSelection)
 {
 	if (!!_outputSelection && !_outputSelection.isObject())
-		return formatFatalError("JSONError", "\"settings.outputSelection\" must be an object");
+		return formatFatalError(Error::Type::JSONError, "\"settings.outputSelection\" must be an object");
 
 	for (auto const& sourceName: _outputSelection.getMemberNames())
 	{
@@ -532,7 +531,7 @@ std::optional<Json::Value> checkOutputSelection(Json::Value const& _outputSelect
 
 		if (!sourceVal.isObject())
 			return formatFatalError(
-				"JSONError",
+				Error::Type::JSONError,
 				"\"settings.outputSelection." + sourceName + "\" must be an object"
 			);
 
@@ -542,7 +541,7 @@ std::optional<Json::Value> checkOutputSelection(Json::Value const& _outputSelect
 
 			if (!contractVal.isArray())
 				return formatFatalError(
-					"JSONError",
+					Error::Type::JSONError,
 					"\"settings.outputSelection." +
 					sourceName +
 					"." +
@@ -553,7 +552,7 @@ std::optional<Json::Value> checkOutputSelection(Json::Value const& _outputSelect
 			for (auto const& output: contractVal)
 				if (!output.isString())
 					return formatFatalError(
-						"JSONError",
+						Error::Type::JSONError,
 						"\"settings.outputSelection." +
 						sourceName +
 						"." +
@@ -578,7 +577,7 @@ std::variant<OptimiserSettings, Json::Value> parseOptimizerSettings(Json::Value
 	if (_jsonInput.isMember("enabled"))
 	{
 		if (!_jsonInput["enabled"].isBool())
-			return formatFatalError("JSONError", "The \"enabled\" setting must be a Boolean.");
+			return formatFatalError(Error::Type::JSONError, "The \"enabled\" setting must be a Boolean.");
 
 		if (_jsonInput["enabled"].asBool())
 			settings = OptimiserSettings::standard();
@@ -587,7 +586,7 @@ std::variant<OptimiserSettings, Json::Value> parseOptimizerSettings(Json::Value
 	if (_jsonInput.isMember("runs"))
 	{
 		if (!_jsonInput["runs"].isUInt())
-			return formatFatalError("JSONError", "The \"runs\" setting must be an unsigned number.");
+			return formatFatalError(Error::Type::JSONError, "The \"runs\" setting must be an unsigned number.");
 		settings.expectedExecutionsPerDeployment = _jsonInput["runs"].asUInt();
 	}
 
@@ -617,7 +616,7 @@ std::variant<OptimiserSettings, Json::Value> parseOptimizerSettings(Json::Value
 		if (details.isMember("yulDetails"))
 		{
 			if (!settings.runYulOptimiser)
-				return formatFatalError("JSONError", "\"Providing yulDetails requires Yul optimizer to be enabled.");
+				return formatFatalError(Error::Type::JSONError, "\"Providing yulDetails requires Yul optimizer to be enabled.");
 
 			if (auto result = checkKeys(details["yulDetails"], {"stackAllocation", "optimizerSteps"}, "settings.optimizer.details.yulDetails"))
 				return *result;
@@ -638,7 +637,7 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 	InputsAndSettings ret;
 
 	if (!_input.isObject())
-		return formatFatalError("JSONError", "Input is not a JSON object.");
+		return formatFatalError(Error::Type::JSONError, "Input is not a JSON object.");
 
 	if (auto result = checkRootKeys(_input))
 		return *result;
@@ -648,10 +647,10 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 	Json::Value const& sources = _input["sources"];
 
 	if (!sources.isObject() && !sources.isNull())
-		return formatFatalError("JSONError", "\"sources\" is not a JSON object.");
+		return formatFatalError(Error::Type::JSONError, "\"sources\" is not a JSON object.");
 
 	if (sources.empty())
-		return formatFatalError("JSONError", "No input sources specified.");
+		return formatFatalError(Error::Type::JSONError, "No input sources specified.");
 
 	ret.errors = Json::arrayValue;
 
@@ -670,8 +669,7 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 			string content = sources[sourceName]["content"].asString();
 			if (!hash.empty() && !hashMatchesContent(hash, content))
 				ret.errors.append(formatError(
-					Error::Severity::Error,
-					"IOError",
+					Error::Type::IOError,
 					"general",
 					"Mismatch between content and supplied hash for \"" + sourceName + "\""
 				));
@@ -681,22 +679,21 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 		else if (sources[sourceName]["urls"].isArray())
 		{
 			if (!m_readFile)
-				return formatFatalError("JSONError", "No import callback supplied, but URL is requested.");
+				return formatFatalError(Error::Type::JSONError, "No import callback supplied, but URL is requested.");
 
-			bool found = false;
 			vector<string> failures;
+			bool found = false;
 
 			for (auto const& url: sources[sourceName]["urls"])
 			{
 				if (!url.isString())
-					return formatFatalError("JSONError", "URL must be a string.");
+					return formatFatalError(Error::Type::JSONError, "URL must be a string.");
 				ReadCallback::Result result = m_readFile(ReadCallback::kindString(ReadCallback::Kind::ReadFile), url.asString());
 				if (result.success)
 				{
 					if (!hash.empty() && !hashMatchesContent(hash, result.responseOrErrorMessage))
 						ret.errors.append(formatError(
-							Error::Severity::Error,
-							"IOError",
+							Error::Type::IOError,
 							"general",
 							"Mismatch between content and supplied hash for \"" + sourceName + "\" at \"" + url.asString() + "\""
 						));
@@ -715,15 +712,14 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 			{
 				/// If the import succeeded, let mark all the others as warnings, otherwise all of them are errors.
 				ret.errors.append(formatError(
-					found ? Error::Severity::Warning : Error::Severity::Error,
-					"IOError",
+					found ? Error::Type::Warning : Error::Type::IOError,
 					"general",
 					failure
 				));
 			}
 		}
 		else
-			return formatFatalError("JSONError", "Invalid input source specified.");
+			return formatFatalError(Error::Type::JSONError, "Invalid input source specified.");
 	}
 
 	Json::Value const& auxInputs = _input["auxiliaryInput"];
@@ -737,7 +733,7 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 		if (!!smtlib2Responses)
 		{
 			if (!smtlib2Responses.isObject())
-				return formatFatalError("JSONError", "\"auxiliaryInput.smtlib2responses\" must be an object.");
+				return formatFatalError(Error::Type::JSONError, "\"auxiliaryInput.smtlib2responses\" must be an object.");
 
 			for (auto const& hashString: smtlib2Responses.getMemberNames())
 			{
@@ -748,12 +744,12 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 				}
 				catch (util::BadHexCharacter const&)
 				{
-					return formatFatalError("JSONError", "Invalid hex encoding of SMTLib2 auxiliary input.");
+					return formatFatalError(Error::Type::JSONError, "Invalid hex encoding of SMTLib2 auxiliary input.");
 				}
 
 				if (!smtlib2Responses[hashString].isString())
 					return formatFatalError(
-						"JSONError",
+						Error::Type::JSONError,
 						"\"smtlib2Responses." + hashString + "\" must be a string."
 					);
 
@@ -770,10 +766,10 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 	if (settings.isMember("stopAfter"))
 	{
 		if (!settings["stopAfter"].isString())
-			return formatFatalError("JSONError", "\"settings.stopAfter\" must be a string.");
+			return formatFatalError(Error::Type::JSONError, "\"settings.stopAfter\" must be a string.");
 
 		if (settings["stopAfter"].asString() != "parsing")
-			return formatFatalError("JSONError", "Invalid value for \"settings.stopAfter\". Only valid value is \"parsing\".");
+			return formatFatalError(Error::Type::JSONError, "Invalid value for \"settings.stopAfter\". Only valid value is \"parsing\".");
 
 		ret.stopAfter = CompilerStack::State::Parsed;
 	}
@@ -781,24 +777,24 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 	if (settings.isMember("parserErrorRecovery"))
 	{
 		if (!settings["parserErrorRecovery"].isBool())
-			return formatFatalError("JSONError", "\"settings.parserErrorRecovery\" must be a Boolean.");
+			return formatFatalError(Error::Type::JSONError, "\"settings.parserErrorRecovery\" must be a Boolean.");
 		ret.parserErrorRecovery = settings["parserErrorRecovery"].asBool();
 	}
 
 	if (settings.isMember("viaIR"))
 	{
 		if (!settings["viaIR"].isBool())
-			return formatFatalError("JSONError", "\"settings.viaIR\" must be a Boolean.");
+			return formatFatalError(Error::Type::JSONError, "\"settings.viaIR\" must be a Boolean.");
 		ret.viaIR = settings["viaIR"].asBool();
 	}
 
 	if (settings.isMember("evmVersion"))
 	{
 		if (!settings["evmVersion"].isString())
-			return formatFatalError("JSONError", "evmVersion must be a string.");
+			return formatFatalError(Error::Type::JSONError, "evmVersion must be a string.");
 		std::optional<langutil::EVMVersion> version = langutil::EVMVersion::fromString(settings["evmVersion"].asString());
 		if (!version)
-			return formatFatalError("JSONError", "Invalid EVM version requested.");
+			return formatFatalError(Error::Type::JSONError, "Invalid EVM version requested.");
 		ret.evmVersion = *version;
 	}
 
@@ -810,13 +806,13 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 		if (settings["debug"].isMember("revertStrings"))
 		{
 			if (!settings["debug"]["revertStrings"].isString())
-				return formatFatalError("JSONError", "settings.debug.revertStrings must be a string.");
+				return formatFatalError(Error::Type::JSONError, "settings.debug.revertStrings must be a string.");
 			std::optional<RevertStrings> revertStrings = revertStringsFromString(settings["debug"]["revertStrings"].asString());
 			if (!revertStrings)
-				return formatFatalError("JSONError", "Invalid value for settings.debug.revertStrings.");
+				return formatFatalError(Error::Type::JSONError, "Invalid value for settings.debug.revertStrings.");
 			if (*revertStrings == RevertStrings::VerboseDebug)
 				return formatFatalError(
-					"UnimplementedFeatureError",
+					Error::Type::UnimplementedFeatureError,
 					"Only \"default\", \"strip\" and \"debug\" are implemented for settings.debug.revertStrings for now."
 				);
 			ret.revertStrings = *revertStrings;
@@ -825,7 +821,7 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 		if (settings["debug"].isMember("debugInfo"))
 		{
 			if (!settings["debug"]["debugInfo"].isArray())
-				return formatFatalError("JSONError", "settings.debug.debugInfo must be an array.");
+				return formatFatalError(Error::Type::JSONError, "settings.debug.debugInfo must be an array.");
 
 			vector<string> components;
 			for (Json::Value const& arrayValue: settings["debug"]["debugInfo"])
@@ -836,11 +832,11 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 				true /* _acceptWildcards */
 			);
 			if (!debugInfoSelection.has_value())
-				return formatFatalError("JSONError", "Invalid value in settings.debug.debugInfo.");
+				return formatFatalError(Error::Type::JSONError, "Invalid value in settings.debug.debugInfo.");
 
 			if (debugInfoSelection->snippet && !debugInfoSelection->location)
 				return formatFatalError(
-					"JSONError",
+					Error::Type::JSONError,
 					"To use 'snippet' with settings.debug.debugInfo you must select also 'location'."
 				);
 
@@ -849,16 +845,16 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 	}
 
 	if (settings.isMember("remappings") && !settings["remappings"].isArray())
-		return formatFatalError("JSONError", "\"settings.remappings\" must be an array of strings.");
+		return formatFatalError(Error::Type::JSONError, "\"settings.remappings\" must be an array of strings.");
 
 	for (auto const& remapping: settings.get("remappings", Json::Value()))
 	{
 		if (!remapping.isString())
-			return formatFatalError("JSONError", "\"settings.remappings\" must be an array of strings");
+			return formatFatalError(Error::Type::JSONError, "\"settings.remappings\" must be an array of strings");
 		if (auto r = ImportRemapper::parseRemapping(remapping.asString()))
 			ret.remappings.emplace_back(std::move(*r));
 		else
-			return formatFatalError("JSONError", "Invalid remapping: \"" + remapping.asString() + "\"");
+			return formatFatalError(Error::Type::JSONError, "Invalid remapping: \"" + remapping.asString() + "\"");
 	}
 
 	if (settings.isMember("optimizer"))
@@ -872,27 +868,27 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 
 	Json::Value jsonLibraries = settings.get("libraries", Json::Value(Json::objectValue));
 	if (!jsonLibraries.isObject())
-		return formatFatalError("JSONError", "\"libraries\" is not a JSON object.");
+		return formatFatalError(Error::Type::JSONError, "\"libraries\" is not a JSON object.");
 	for (auto const& sourceName: jsonLibraries.getMemberNames())
 	{
 		auto const& jsonSourceName = jsonLibraries[sourceName];
 		if (!jsonSourceName.isObject())
-			return formatFatalError("JSONError", "Library entry is not a JSON object.");
+			return formatFatalError(Error::Type::JSONError, "Library entry is not a JSON object.");
 		for (auto const& library: jsonSourceName.getMemberNames())
 		{
 			if (!jsonSourceName[library].isString())
-				return formatFatalError("JSONError", "Library address must be a string.");
+				return formatFatalError(Error::Type::JSONError, "Library address must be a string.");
 			string address = jsonSourceName[library].asString();
 
 			if (!boost::starts_with(address, "0x"))
 				return formatFatalError(
-					"JSONError",
+					Error::Type::JSONError,
 					"Library address is not prefixed with \"0x\"."
 				);
 
 			if (address.length() != 42)
 				return formatFatalError(
-					"JSONError",
+					Error::Type::JSONError,
 					"Library address is of invalid length."
 				);
 
@@ -903,7 +899,7 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 			catch (util::BadHexCharacter const&)
 			{
 				return formatFatalError(
-					"JSONError",
+					Error::Type::JSONError,
 					"Invalid library address (\"" + address + "\") supplied."
 				);
 			}
@@ -936,7 +932,7 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 
 	if (ret.stopAfter != CompilerStack::State::CompilationSuccessful && isBinaryRequested(ret.outputSelection))
 		return formatFatalError(
-			"JSONError",
+			Error::Type::JSONError,
 			"Requested output selection conflicts with \"settings.stopAfter\"."
 		);
 
@@ -949,29 +945,29 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 	{
 		auto const& sources = modelCheckerSettings["contracts"];
 		if (!sources.isObject() && !sources.isNull())
-			return formatFatalError("JSONError", "settings.modelChecker.contracts is not a JSON object.");
+			return formatFatalError(Error::Type::JSONError, "settings.modelChecker.contracts is not a JSON object.");
 
 		map<string, set<string>> sourceContracts;
 		for (auto const& source: sources.getMemberNames())
 		{
 			if (source.empty())
-				return formatFatalError("JSONError", "Source name cannot be empty.");
+				return formatFatalError(Error::Type::JSONError, "Source name cannot be empty.");
 
 			auto const& contracts = sources[source];
 			if (!contracts.isArray())
-				return formatFatalError("JSONError", "Source contracts must be an array.");
+				return formatFatalError(Error::Type::JSONError, "Source contracts must be an array.");
 
 			for (auto const& contract: contracts)
 			{
 				if (!contract.isString())
-					return formatFatalError("JSONError", "Every contract in settings.modelChecker.contracts must be a string.");
+					return formatFatalError(Error::Type::JSONError, "Every contract in settings.modelChecker.contracts must be a string.");
 				if (contract.asString().empty())
-					return formatFatalError("JSONError", "Contract name cannot be empty.");
+					return formatFatalError(Error::Type::JSONError, "Contract name cannot be empty.");
 				sourceContracts[source].insert(contract.asString());
 			}
 
 			if (sourceContracts[source].empty())
-				return formatFatalError("JSONError", "Source contracts must be a non-empty array.");
+				return formatFatalError(Error::Type::JSONError, "Source contracts must be a non-empty array.");
 		}
 		ret.modelCheckerSettings.contracts = {std::move(sourceContracts)};
 	}
@@ -980,17 +976,17 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 	{
 		auto const& divModNoSlacks = modelCheckerSettings["divModNoSlacks"];
 		if (!divModNoSlacks.isBool())
-			return formatFatalError("JSONError", "settings.modelChecker.divModNoSlacks must be a Boolean.");
+			return formatFatalError(Error::Type::JSONError, "settings.modelChecker.divModNoSlacks must be a Boolean.");
 		ret.modelCheckerSettings.divModNoSlacks = divModNoSlacks.asBool();
 	}
 
 	if (modelCheckerSettings.isMember("engine"))
 	{
 		if (!modelCheckerSettings["engine"].isString())
-			return formatFatalError("JSONError", "settings.modelChecker.engine must be a string.");
+			return formatFatalError(Error::Type::JSONError, "settings.modelChecker.engine must be a string.");
 		std::optional<ModelCheckerEngine> engine = ModelCheckerEngine::fromString(modelCheckerSettings["engine"].asString());
 		if (!engine)
-			return formatFatalError("JSONError", "Invalid model checker engine requested.");
+			return formatFatalError(Error::Type::JSONError, "Invalid model checker engine requested.");
 		ret.modelCheckerSettings.engine = *engine;
 	}
 
@@ -998,19 +994,19 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 	{
 		auto const& invariantsArray = modelCheckerSettings["invariants"];
 		if (!invariantsArray.isArray())
-			return formatFatalError("JSONError", "settings.modelChecker.invariants must be an array.");
+			return formatFatalError(Error::Type::JSONError, "settings.modelChecker.invariants must be an array.");
 
 		ModelCheckerInvariants invariants;
 		for (auto const& i: invariantsArray)
 		{
 			if (!i.isString())
-				return formatFatalError("JSONError", "Every invariant type in settings.modelChecker.invariants must be a string.");
+				return formatFatalError(Error::Type::JSONError, "Every invariant type in settings.modelChecker.invariants must be a string.");
 			if (!invariants.setFromString(i.asString()))
-				return formatFatalError("JSONError", "Invalid model checker invariants requested.");
+				return formatFatalError(Error::Type::JSONError, "Invalid model checker invariants requested.");
 		}
 
 		if (invariants.invariants.empty())
-			return formatFatalError("JSONError", "settings.modelChecker.invariants must be a non-empty array.");
+			return formatFatalError(Error::Type::JSONError, "settings.modelChecker.invariants must be a non-empty array.");
 
 		ret.modelCheckerSettings.invariants = invariants;
 	}
@@ -1019,7 +1015,7 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 	{
 		auto const& showUnproved = modelCheckerSettings["showUnproved"];
 		if (!showUnproved.isBool())
-			return formatFatalError("JSONError", "settings.modelChecker.showUnproved must be a Boolean value.");
+			return formatFatalError(Error::Type::JSONError, "settings.modelChecker.showUnproved must be a Boolean value.");
 		ret.modelCheckerSettings.showUnproved = showUnproved.asBool();
 	}
 
@@ -1027,15 +1023,15 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 	{
 		auto const& solversArray = modelCheckerSettings["solvers"];
 		if (!solversArray.isArray())
-			return formatFatalError("JSONError", "settings.modelChecker.solvers must be an array.");
+			return formatFatalError(Error::Type::JSONError, "settings.modelChecker.solvers must be an array.");
 
 		smtutil::SMTSolverChoice solvers;
 		for (auto const& s: solversArray)
 		{
 			if (!s.isString())
-				return formatFatalError("JSONError", "Every target in settings.modelChecker.solvers must be a string.");
+				return formatFatalError(Error::Type::JSONError, "Every target in settings.modelChecker.solvers must be a string.");
 			if (!solvers.setSolver(s.asString()))
-				return formatFatalError("JSONError", "Invalid model checker solvers requested.");
+				return formatFatalError(Error::Type::JSONError, "Invalid model checker solvers requested.");
 		}
 
 		ret.modelCheckerSettings.solvers = solvers;
@@ -1045,19 +1041,19 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 	{
 		auto const& targetsArray = modelCheckerSettings["targets"];
 		if (!targetsArray.isArray())
-			return formatFatalError("JSONError", "settings.modelChecker.targets must be an array.");
+			return formatFatalError(Error::Type::JSONError, "settings.modelChecker.targets must be an array.");
 
 		ModelCheckerTargets targets;
 		for (auto const& t: targetsArray)
 		{
 			if (!t.isString())
-				return formatFatalError("JSONError", "Every target in settings.modelChecker.targets must be a string.");
+				return formatFatalError(Error::Type::JSONError, "Every target in settings.modelChecker.targets must be a string.");
 			if (!targets.setFromString(t.asString()))
-				return formatFatalError("JSONError", "Invalid model checker targets requested.");
+				return formatFatalError(Error::Type::JSONError, "Invalid model checker targets requested.");
 		}
 
 		if (targets.targets.empty())
-			return formatFatalError("JSONError", "settings.modelChecker.targets must be a non-empty array.");
+			return formatFatalError(Error::Type::JSONError, "settings.modelChecker.targets must be a non-empty array.");
 
 		ret.modelCheckerSettings.targets = targets;
 	}
@@ -1065,7 +1061,7 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 	if (modelCheckerSettings.isMember("timeout"))
 	{
 		if (!modelCheckerSettings["timeout"].isUInt())
-			return formatFatalError("JSONError", "settings.modelChecker.timeout must be an unsigned integer.");
+			return formatFatalError(Error::Type::JSONError, "settings.modelChecker.timeout must be an unsigned integer.");
 		ret.modelCheckerSettings.timeout = modelCheckerSettings["timeout"].asUInt();
 	}
 
@@ -1116,8 +1112,7 @@ Json::Value StandardCompiler::compileSolidity(StandardCompiler::InputsAndSetting
 			errors.append(formatErrorWithException(
 				compilerStack,
 				*error,
-				Error::errorSeverity(err.type()),
-				err.typeName(),
+				err.type(),
 				"general",
 				"",
 				err.errorId()
@@ -1130,8 +1125,7 @@ Json::Value StandardCompiler::compileSolidity(StandardCompiler::InputsAndSetting
 		errors.append(formatErrorWithException(
 			compilerStack,
 			_error,
-			Error::Severity::Error,
-			_error.typeName(),
+			_error.type(),
 			"general",
 			"Uncaught error: "
 		));
@@ -1140,8 +1134,7 @@ Json::Value StandardCompiler::compileSolidity(StandardCompiler::InputsAndSetting
 	catch (FatalError const& _exception)
 	{
 		errors.append(formatError(
-			Error::Severity::Error,
-			"FatalError",
+			Error::Type::FatalError,
 			"general",
 			"Uncaught fatal error: " + boost::diagnostic_information(_exception)
 		));
@@ -1151,8 +1144,7 @@ Json::Value StandardCompiler::compileSolidity(StandardCompiler::InputsAndSetting
 		errors.append(formatErrorWithException(
 			compilerStack,
 			_exception,
-			Error::Severity::Error,
-			"CompilerError",
+			Error::Type::CompilerError,
 			"general",
 			"Compiler error (" + _exception.lineInfo() + ")"
 		));
@@ -1162,8 +1154,7 @@ Json::Value StandardCompiler::compileSolidity(StandardCompiler::InputsAndSetting
 		errors.append(formatErrorWithException(
 			compilerStack,
 			_exception,
-			Error::Severity::Error,
-			"InternalCompilerError",
+			Error::Type::InternalCompilerError,
 			"general",
 			"Internal compiler error (" + _exception.lineInfo() + ")"
 		));
@@ -1173,8 +1164,7 @@ Json::Value StandardCompiler::compileSolidity(StandardCompiler::InputsAndSetting
 		errors.append(formatErrorWithException(
 			compilerStack,
 			_exception,
-			Error::Severity::Error,
-			"UnimplementedFeatureError",
+			Error::Type::UnimplementedFeatureError,
 			"general",
 			"Unimplemented feature (" + _exception.lineInfo() + ")"
 		));
@@ -1184,8 +1174,7 @@ Json::Value StandardCompiler::compileSolidity(StandardCompiler::InputsAndSetting
 		errors.append(formatErrorWithException(
 			compilerStack,
 			_exception,
-			Error::Severity::Error,
-			"YulException",
+			Error::Type::YulException,
 			"general",
 			"Yul exception"
 		));
@@ -1195,8 +1184,7 @@ Json::Value StandardCompiler::compileSolidity(StandardCompiler::InputsAndSetting
 		errors.append(formatErrorWithException(
 			compilerStack,
 			_exception,
-			Error::Severity::Error,
-			"SMTLogicException",
+			Error::Type::SMTLogicException,
 			"general",
 			"SMT logic exception"
 		));
@@ -1204,8 +1192,7 @@ Json::Value StandardCompiler::compileSolidity(StandardCompiler::InputsAndSetting
 	catch (util::Exception const& _exception)
 	{
 		errors.append(formatError(
-			Error::Severity::Error,
-			"Exception",
+			Error::Type::Exception,
 			"general",
 			"Exception during compilation: " + boost::diagnostic_information(_exception)
 		));
@@ -1213,8 +1200,7 @@ Json::Value StandardCompiler::compileSolidity(StandardCompiler::InputsAndSetting
 	catch (std::exception const& _exception)
 	{
 		errors.append(formatError(
-			Error::Severity::Error,
-			"Exception",
+			Error::Type::Exception,
 			"general",
 			"Unknown exception during compilation: " + boost::diagnostic_information(_exception)
 		));
@@ -1222,8 +1208,7 @@ Json::Value StandardCompiler::compileSolidity(StandardCompiler::InputsAndSetting
 	catch (...)
 	{
 		errors.append(formatError(
-			Error::Severity::Error,
-			"Exception",
+			Error::Type::Exception,
 			"general",
 			"Unknown exception during compilation: " + boost::current_exception_diagnostic_information()
 		));
@@ -1240,7 +1225,7 @@ Json::Value StandardCompiler::compileSolidity(StandardCompiler::InputsAndSetting
 		((binariesRequested && !compilationSuccess) || !analysisPerformed) &&
 		(errors.empty() && _inputsAndSettings.stopAfter >= CompilerStack::State::AnalysisPerformed)
 	)
-		return formatFatalError("InternalCompilerError", "No error reported, but compilation failed.");
+		return formatFatalError(Error::Type::InternalCompilerError, "No error reported, but compilation failed.");
 
 	Json::Value output = Json::objectValue;
 
@@ -1376,8 +1361,7 @@ Json::Value StandardCompiler::compileYul(InputsAndSettings _inputsAndSettings)
 	if (_inputsAndSettings.sources.size() != 1)
 	{
 		output["errors"].append(formatError(
-			Error::Severity::Error,
-			"JSONError",
+			Error::Type::JSONError,
 			"general",
 			"Yul mode only supports exactly one input file."
 		));
@@ -1386,8 +1370,7 @@ Json::Value StandardCompiler::compileYul(InputsAndSettings _inputsAndSettings)
 	if (!_inputsAndSettings.smtLib2Responses.empty())
 	{
 		output["errors"].append(formatError(
-			Error::Severity::Error,
-			"JSONError",
+			Error::Type::JSONError,
 			"general",
 			"Yul mode does not support smtlib2responses."
 		));
@@ -1396,8 +1379,7 @@ Json::Value StandardCompiler::compileYul(InputsAndSettings _inputsAndSettings)
 	if (!_inputsAndSettings.remappings.empty())
 	{
 		output["errors"].append(formatError(
-			Error::Severity::Error,
-			"JSONError",
+			Error::Type::JSONError,
 			"general",
 			"Field \"settings.remappings\" cannot be used for Yul."
 		));
@@ -1406,8 +1388,7 @@ Json::Value StandardCompiler::compileYul(InputsAndSettings _inputsAndSettings)
 	if (_inputsAndSettings.revertStrings != RevertStrings::Default)
 	{
 		output["errors"].append(formatError(
-			Error::Severity::Error,
-			"JSONError",
+			Error::Type::JSONError,
 			"general",
 			"Field \"settings.debug.revertStrings\" cannot be used for Yul."
 		));
@@ -1429,8 +1410,7 @@ Json::Value StandardCompiler::compileYul(InputsAndSettings _inputsAndSettings)
 	if (!stack.parseAndAnalyze(sourceName, sourceContents) && stack.errors().empty())
 	{
 		output["errors"].append(formatError(
-			Error::Severity::Error,
-			"InternalCompilerError",
+			Error::Type::InternalCompilerError,
 			"general",
 			"No error reported, but compilation failed."
 		));
@@ -1446,8 +1426,7 @@ Json::Value StandardCompiler::compileYul(InputsAndSettings _inputsAndSettings)
 			output["errors"].append(formatErrorWithException(
 				stack,
 				*error,
-				Error::errorSeverity(err->type()),
-				err->typeName(),
+				err->type(),
 				"general",
 				""
 			));
@@ -1523,23 +1502,23 @@ Json::Value StandardCompiler::compile(Json::Value const& _input) noexcept
 		else if (settings.language == "Yul")
 			return compileYul(std::move(settings));
 		else
-			return formatFatalError("JSONError", "Only \"Solidity\" or \"Yul\" is supported as a language.");
+			return formatFatalError(Error::Type::JSONError, "Only \"Solidity\" or \"Yul\" is supported as a language.");
 	}
 	catch (Json::LogicError const& _exception)
 	{
-		return formatFatalError("InternalCompilerError", string("JSON logic exception: ") + _exception.what());
+		return formatFatalError(Error::Type::InternalCompilerError, string("JSON logic exception: ") + _exception.what());
 	}
 	catch (Json::RuntimeError const& _exception)
 	{
-		return formatFatalError("InternalCompilerError", string("JSON runtime exception: ") + _exception.what());
+		return formatFatalError(Error::Type::InternalCompilerError, string("JSON runtime exception: ") + _exception.what());
 	}
 	catch (util::Exception const& _exception)
 	{
-		return formatFatalError("InternalCompilerError", "Internal exception in StandardCompiler::compile: " + boost::diagnostic_information(_exception));
+		return formatFatalError(Error::Type::InternalCompilerError, "Internal exception in StandardCompiler::compile: " + boost::diagnostic_information(_exception));
 	}
 	catch (...)
 	{
-		return formatFatalError("InternalCompilerError", "Internal exception in StandardCompiler::compile: " +  boost::current_exception_diagnostic_information());
+		return formatFatalError(Error::Type::InternalCompilerError, "Internal exception in StandardCompiler::compile: " +  boost::current_exception_diagnostic_information());
 	}
 }
 
@@ -1550,7 +1529,7 @@ string StandardCompiler::compile(string const& _input) noexcept
 	try
 	{
 		if (!util::jsonParseStrict(_input, input, &errors))
-			return util::jsonPrint(formatFatalError("JSONError", errors), m_jsonPrintingFormat);
+			return util::jsonPrint(formatFatalError(Error::Type::JSONError, errors), m_jsonPrintingFormat);
 	}
 	catch (...)
 	{
diff --git a/libsolidity/lsp/LanguageServer.cpp b/libsolidity/lsp/LanguageServer.cpp
index ce68dbef3..1a1f5faf0 100644
--- a/libsolidity/lsp/LanguageServer.cpp
+++ b/libsolidity/lsp/LanguageServer.cpp
@@ -286,7 +286,7 @@ void LanguageServer::compileAndUpdateDiagnostics()
 		jsonDiag["source"] = "solc";
 		jsonDiag["severity"] = toDiagnosticSeverity(error->type());
 		jsonDiag["code"] = Json::UInt64{error->errorId().error};
-		string message = error->typeName() + ":";
+		string message = Error::formatErrorType(error->type()) + ":";
 		if (string const* comment = error->comment())
 			message += " " + *comment;
 		jsonDiag["message"] = std::move(message);
diff --git a/solc/CommandLineInterface.cpp b/solc/CommandLineInterface.cpp
index e215405a1..ccaa8df94 100644
--- a/solc/CommandLineInterface.cpp
+++ b/solc/CommandLineInterface.cpp
@@ -765,7 +765,10 @@ void CommandLineInterface::compile()
 	catch (CompilerError const& _exception)
 	{
 		m_hasOutput = true;
-		formatter.printExceptionInformation(_exception, "Compiler error");
+		formatter.printExceptionInformation(
+			_exception,
+			Error::errorSeverity(Error::Type::CompilerError)
+		);
 		solThrow(CommandLineExecutionError, "");
 	}
 	catch (Error const& _error)
@@ -778,7 +781,7 @@ void CommandLineInterface::compile()
 		else
 		{
 			m_hasOutput = true;
-			formatter.printExceptionInformation(_error, _error.typeName());
+			formatter.printExceptionInformation(_error, Error::errorSeverity(_error.type()));
 			solThrow(CommandLineExecutionError, "");
 		}
 	}
diff --git a/test/cmdlineTests/standard_urls_existing_and_missing/contract.sol b/test/cmdlineTests/standard_urls_existing_and_missing/contract.sol
new file mode 100644
index 000000000..a32f63f78
--- /dev/null
+++ b/test/cmdlineTests/standard_urls_existing_and_missing/contract.sol
@@ -0,0 +1,2 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity *;
diff --git a/test/cmdlineTests/standard_urls_existing_and_missing/input.json b/test/cmdlineTests/standard_urls_existing_and_missing/input.json
new file mode 100644
index 000000000..686e8128e
--- /dev/null
+++ b/test/cmdlineTests/standard_urls_existing_and_missing/input.json
@@ -0,0 +1,13 @@
+{
+    "language": "Solidity",
+    "sources": {
+        "url_not_found.sol": {
+            "urls": [
+                "standard_urls_existing_and_missing/non-existent-contract-1.sol",
+                "standard_urls_existing_and_missing/contract.sol",
+                "standard_urls_existing_and_missing/non-existent-contract-2.sol"
+            ]
+        }
+    },
+    "settings": {"outputSelection": {"*": { "*": ["metadata", "evm.bytecode"]}}}
+}
diff --git a/test/cmdlineTests/standard_urls_existing_and_missing/output.json b/test/cmdlineTests/standard_urls_existing_and_missing/output.json
new file mode 100644
index 000000000..8cb0cc4c7
--- /dev/null
+++ b/test/cmdlineTests/standard_urls_existing_and_missing/output.json
@@ -0,0 +1 @@
+{"errors":[{"component":"general","formattedMessage":"Cannot import url (\"standard_urls_existing_and_missing/non-existent-contract-1.sol\"): File not found. Searched the following locations: \"\".","message":"Cannot import url (\"standard_urls_existing_and_missing/non-existent-contract-1.sol\"): File not found. Searched the following locations: \"\".","severity":"warning","type":"Warning"}],"sources":{"url_not_found.sol":{"id":0}}}
diff --git a/test/cmdlineTests/standard_urls_missing/contract.sol b/test/cmdlineTests/standard_urls_missing/contract.sol
new file mode 100644
index 000000000..a32f63f78
--- /dev/null
+++ b/test/cmdlineTests/standard_urls_missing/contract.sol
@@ -0,0 +1,2 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity *;
diff --git a/test/cmdlineTests/standard_urls_missing/input.json b/test/cmdlineTests/standard_urls_missing/input.json
new file mode 100644
index 000000000..fecc50eb0
--- /dev/null
+++ b/test/cmdlineTests/standard_urls_missing/input.json
@@ -0,0 +1,13 @@
+{
+    "language": "Solidity",
+    "sources": {
+        "url_not_found.sol": {
+            "urls": [
+                "standard_urls_missing/non-existent-contract-1.sol",
+                "standard_urls_missing/non-existent-contract.sol",
+                "standard_urls_missing/non-existent-contract-2.sol"
+            ]
+        }
+    },
+    "settings": {"outputSelection": {"*": { "*": ["metadata", "evm.bytecode"]}}}
+}
diff --git a/test/cmdlineTests/standard_urls_missing/output.json b/test/cmdlineTests/standard_urls_missing/output.json
new file mode 100644
index 000000000..2bead4831
--- /dev/null
+++ b/test/cmdlineTests/standard_urls_missing/output.json
@@ -0,0 +1 @@
+{"errors":[{"component":"general","formattedMessage":"Cannot import url (\"standard_urls_missing/non-existent-contract-1.sol\"): File not found. Searched the following locations: \"\".","message":"Cannot import url (\"standard_urls_missing/non-existent-contract-1.sol\"): File not found. Searched the following locations: \"\".","severity":"error","type":"IOError"},{"component":"general","formattedMessage":"Cannot import url (\"standard_urls_missing/non-existent-contract.sol\"): File not found. Searched the following locations: \"\".","message":"Cannot import url (\"standard_urls_missing/non-existent-contract.sol\"): File not found. Searched the following locations: \"\".","severity":"error","type":"IOError"},{"component":"general","formattedMessage":"Cannot import url (\"standard_urls_missing/non-existent-contract-2.sol\"): File not found. Searched the following locations: \"\".","message":"Cannot import url (\"standard_urls_missing/non-existent-contract-2.sol\"): File not found. Searched the following locations: \"\".","severity":"error","type":"IOError"}],"sources":{}}
diff --git a/test/libsolidity/ErrorCheck.cpp b/test/libsolidity/ErrorCheck.cpp
index 418d7cc99..8a8b2166c 100644
--- a/test/libsolidity/ErrorCheck.cpp
+++ b/test/libsolidity/ErrorCheck.cpp
@@ -71,7 +71,7 @@ string solidity::frontend::test::searchErrors(ErrorList const& _errors, vector<p
 				break;
 			}
 		if (!found)
-			return "Unexpected error: " + error->typeName() + ": " + msg;
+			return "Unexpected error: " + Error::formatErrorType(error->type()) + ": " + msg;
 	}
 	if (!expectations.empty())
 	{
diff --git a/test/libsolidity/SyntaxTest.cpp b/test/libsolidity/SyntaxTest.cpp
index d3e512450..ee3c4b4b0 100644
--- a/test/libsolidity/SyntaxTest.cpp
+++ b/test/libsolidity/SyntaxTest.cpp
@@ -145,7 +145,7 @@ void SyntaxTest::filterObtainedErrors()
 			}
 		}
 		m_errorList.emplace_back(SyntaxTestError{
-			currentError->typeName(),
+			Error::formatErrorType(currentError->type()),
 			currentError->errorId(),
 			errorMessage(*currentError),
 			sourceName,
diff --git a/test/libyul/SyntaxTest.cpp b/test/libyul/SyntaxTest.cpp
index 8ab5bb953..cea1d5745 100644
--- a/test/libyul/SyntaxTest.cpp
+++ b/test/libyul/SyntaxTest.cpp
@@ -61,7 +61,7 @@ void SyntaxTest::parseAndAnalyze()
 		}
 
 		m_errorList.emplace_back(SyntaxTestError{
-			error->typeName(),
+			Error::formatErrorType(error->type()),
 			error->errorId(),
 			errorMessage(*error),
 			name,
diff --git a/test/tools/ossfuzz/yulProto_diff_ossfuzz.cpp b/test/tools/ossfuzz/yulProto_diff_ossfuzz.cpp
index c3ad9c9f3..2335bfbf5 100644
--- a/test/tools/ossfuzz/yulProto_diff_ossfuzz.cpp
+++ b/test/tools/ossfuzz/yulProto_diff_ossfuzz.cpp
@@ -79,10 +79,7 @@ DEFINE_PROTO_FUZZER(Program const& _input)
 		SourceReferenceFormatter formatter(std::cout, stack, false, false);
 
 		for (auto const& error: stack.errors())
-			formatter.printExceptionInformation(
-				*error,
-				(error->type() == Error::Type::Warning) ? "Warning" : "Error"
-			);
+			formatter.printExceptionInformation(*error, Error::errorSeverity(error->type()));
 		yulAssert(false, "Proto fuzzer generated malformed program");
 	}