diff --git a/src/Format.h b/src/Format.h
index 0cb760fe36..13bde5ff1f 100644
--- a/src/Format.h
+++ b/src/Format.h
@@ -13,6 +13,7 @@
 #define FORMAT_H
 
 #include "support/docstring.h"
+#include "support/trivstring.h"
 
 #include "OutputParams.h"
 
@@ -54,11 +55,11 @@ public:
 	/// Name fo the parent format
 	std::string const parentFormat() const;
 	///
-	std::string const & name() const { return name_; }
+	std::string const name() const { return name_; }
 	///
 	void setName(std::string const & v) { name_ = v; }
 	///
-	std::string const & extension() const
+	std::string const extension() const
 	{
 		return extension_list_.empty() ? empty_string() : extension_list_[0];
 	}
@@ -67,23 +68,23 @@ public:
 	///
 	void setExtensions(std::string const & v);
 	///
-	std::string const & prettyname() const { return prettyname_; }
+	std::string const prettyname() const { return prettyname_; }
 	///
 	void setPrettyname(std::string const & v) { prettyname_ = v; }
 	///
-	std::string const & shortcut() const { return shortcut_; }
+	std::string const shortcut() const { return shortcut_; }
 	///
 	void setShortcut(std::string const & v) { shortcut_ = v; }
 	///
-	std::string const & viewer() const { return viewer_; }
+	std::string const viewer() const { return viewer_; }
 	///
 	void setViewer(std::string const & v) { viewer_ = v; }
 	///
-	std::string const & editor() const { return editor_; }
+	std::string const editor() const { return editor_; }
 	///
 	void setEditor(std::string const & v) { editor_ = v; }
 	///
-	std::string const & mime() const { return mime_; }
+	std::string const mime() const { return mime_; }
 	///
 	void setMime(std::string const & m) { mime_ = m; }
 	///
@@ -101,13 +102,13 @@ public:
 
 private:
 	/// Internal name. Needs to be unique.
-	std::string name_;
+	trivstring name_;
 	/// Filename extensions, the first one being the default
 	std::vector<std::string> extension_list_;
 	/// Name presented to the user. Needs to be unique.
-	std::string prettyname_;
+	trivstring prettyname_;
 	/// Keyboard shortcut for the View and Export menu.
-	std::string shortcut_;
+	trivstring shortcut_;
 	/*!
 	 * Viewer for this format. Needs to be in the PATH or an absolute
 	 * filename.
@@ -115,9 +116,9 @@ private:
 	 * If it is \c auto the default viewer of the OS for this format is
 	 * used.
 	 */
-	std::string viewer_;
+	trivstring viewer_;
 	/// Editor for this format. \sa viewer_.
-	std::string editor_;
+	trivstring editor_;
 	/*!
 	 * Full MIME type, e.g. "text/x-tex".
 	 * Only types listed by the shared MIME database of freedesktop.org
@@ -125,7 +126,7 @@ private:
 	 * This field may be empty, but it must be unique across all formats
 	 * if it is set.
 	 */
-	std::string mime_;
+	trivstring mime_;
 	///
 	int flags_;
 };
diff --git a/src/support/tests/check_trivstring.cpp b/src/support/tests/check_trivstring.cpp
index f2c44e44ad..1b604657f4 100644
--- a/src/support/tests/check_trivstring.cpp
+++ b/src/support/tests/check_trivstring.cpp
@@ -68,6 +68,13 @@ void test_trivstring()
 	cout << (c == a) << ' ' << (a == c) << endl; // equal strings
 	cout << (a == f) << ' ' << (f == a) << endl; // different strings, same length
 	cout << (a == g) << ' ' << (g == a) << endl; // different strings, different length
+	// operator[]
+	cout << d[1] << d[0] << endl;
+	// substr()
+	cout << d.substr(1) << endl;    // default argument
+	cout << d.substr(1, 1) << endl; // maximum length
+	cout << d.substr(1, 2) << endl; // length larger than max
+	cout << d.substr(2) << endl;    // maximum pos
 }
 
 void test_trivdocstring()
@@ -129,6 +136,13 @@ void test_trivdocstring()
 	cout << (c == a) << ' ' << (a == c) << endl; // equal strings
 	cout << (a == f) << ' ' << (f == a) << endl; // different strings, same length
 	cout << (a == g) << ' ' << (g == a) << endl; // different strings, different length
+	// operator[]
+	cout << static_cast<char>(d[1]) << static_cast<char>(d[0]) << endl;
+	// substr()
+	cout << to_ascii(d.substr(1)) << endl;    // default argument
+	cout << to_ascii(d.substr(1, 1)) << endl; // maximum length
+	cout << to_ascii(d.substr(1, 2)) << endl; // length larger than max
+	cout << to_ascii(d.substr(2)) << endl;    // maximum pos
 }
 
 int main()
diff --git a/src/support/tests/regfiles/trivstring b/src/support/tests/regfiles/trivstring
index 28b6085730..34e64544b1 100644
--- a/src/support/tests/regfiles/trivstring
+++ b/src/support/tests/regfiles/trivstring
@@ -57,6 +57,11 @@ something which does not fit into sso
 0 0
 0 0
 0 0
+24
+2
+2
+2
+
 empty 0
 
 
@@ -116,3 +121,8 @@ something which does not fit into sso
 0 0
 0 0
 0 0
+24
+2
+2
+2
+
diff --git a/src/support/trivstring.cpp b/src/support/trivstring.cpp
index 6fda216674..fad1565c6a 100644
--- a/src/support/trivstring.cpp
+++ b/src/support/trivstring.cpp
@@ -16,6 +16,7 @@
 #ifdef STD_STRING_USES_COW
 #include <algorithm>
 #include <ostream>
+#include <stdexcept>
 
 using namespace std;
 
@@ -31,8 +32,27 @@ trivial_string<Char>::trivial_string(trivial_string const & that) : size_(that.s
 	else if (size_ > 0) {
 		data_ = new Char[size_ + 1];
 		copy(that.data_, that.data_ + size_ + 1, data_);
+	} else {
+		// Happens only for really big Char types
+		data_ = 0;
+	}
+}
+
+
+template<typename Char>
+trivial_string<Char>::trivial_string(Char const * that, size_t n) : size_(n)
+{
+	if (use_sso()) {
+		copy(that, that + size_, data_sso());
+		data_sso()[size_] = '\0';
+	} else if (size_ > 0) {
+		data_ = new Char[size_ + 1];
+		copy(that, that + size_, data_);
+		data_[size_] = '\0';
+	} else {
+		// Happens only for really big Char types
+		data_ = 0;
 	}
-	// else Happens only for really big Char types
 }
 
 
@@ -50,8 +70,10 @@ trivial_string<Char>::trivial_string(
 		data_ = new Char[size_ + 1];
 		copy(that.begin(), that.end(), data_);
 		data_[size_] = '\0';
+	} else {
+		// Happens only for really big Char types
+		data_ = 0;
 	}
-	// else Happens only for really big Char types
 }
 
 
@@ -138,6 +160,20 @@ int trivial_string<Char>::compare(trivial_string const & other) const
 }
 
 
+template trivial_string<char> trivial_string<char>::substr(size_t, size_t) const;
+template trivial_string<char_type> trivial_string<char_type>::substr(size_t, size_t) const;
+template<typename Char>
+trivial_string<Char> trivial_string<Char>::substr(size_t pos, size_t n) const
+{
+	if (pos > length())
+		throw out_of_range("trivial_string::substr");
+	if (n == basic_string<Char, char_traits<Char>, allocator<Char> >::npos)
+		n = length() - pos; 
+	size_t const l = min(pos + n, length());
+	return trivial_string(c_str() + pos, l - pos);
+}
+
+
 template trivial_string<char>::operator string() const;
 template trivial_string<char_type>::operator docstring() const;
 template<typename Char>
@@ -154,8 +190,6 @@ trivial_string<Char>::operator basic_string<Char, char_traits<Char>, allocator<C
 }
 
 
-template char const * trivial_string<char>::c_str() const;
-template char_type const * trivial_string<char_type>::c_str() const;
 template<typename Char> Char const * trivial_string<Char>::c_str() const
 {
 	if (use_sso())
@@ -168,6 +202,14 @@ template<typename Char> Char const * trivial_string<Char>::c_str() const
 }
 
 
+template char trivial_string<char>::operator[](size_t) const;
+template char_type trivial_string<char_type>::operator[](size_t) const;
+template <typename Char> Char trivial_string<Char>::operator[](size_t i) const
+{
+	return c_str()[i];
+}
+
+
 template bool operator<(trivial_string<char> const &,
                         trivial_string<char> const &);
 template bool operator<(trivial_string<char_type> const &,
diff --git a/src/support/trivstring.h b/src/support/trivstring.h
index c83b607d8b..a54889c2d7 100644
--- a/src/support/trivstring.h
+++ b/src/support/trivstring.h
@@ -44,6 +44,8 @@ public:
 	/// Construct a string from a copy of \p that
 	trivial_string(trivial_string const & that);
 	/// Construct a string from a copy of \p that
+	trivial_string(Char const * that, size_t n);
+	/// Construct a string from a copy of \p that
 	trivial_string(std::basic_string<Char, std::char_traits<Char>, std::allocator<Char> > const & that);
 	///
 	~trivial_string() { if (!use_sso()) delete[] data_; }
@@ -59,11 +61,16 @@ public:
 	bool empty() const { return size_ == 0; }
 	/// Is this string ordered before, at the same position or after \p other?
 	int compare(trivial_string const & other) const;
+	/// Return substring of length \p n starting at \p pos
+	trivial_string substr(size_t pos = 0, size_t n = std::basic_string<Char,
+				std::char_traits<Char>, std::allocator<Char> >::npos) const;
 	/// Create a copy as std::basic_string
 	operator std::basic_string<Char, std::char_traits<Char>, std::allocator<Char> >() const;
 	/// Return a C-compatible string, terminated by a 0 character.
 	/// This is never a copy and only valid for the life time of the trivial_string instance.
 	Char const * c_str() const;
+	/// Return character at position \p i (validity of \i is not checked)
+	Char operator[](size_t i) const;
 private:
 	/**
 	 * Whether short string optimization is used.