diff --git a/PdfForQtLib/PdfForQtLib.pro b/PdfForQtLib/PdfForQtLib.pro
index 0fb2e72..a03d561 100644
--- a/PdfForQtLib/PdfForQtLib.pro
+++ b/PdfForQtLib/PdfForQtLib.pro
@@ -70,6 +70,7 @@ SOURCES += \
     sources/pdfsecurityhandler.cpp \
     sources/pdfsignaturehandler.cpp \
     sources/pdfsnapper.cpp \
+    sources/pdfstructuretree.cpp \
     sources/pdftextlayout.cpp \
     sources/pdfutils.cpp \
     sources/pdfwidgettool.cpp \
@@ -128,6 +129,7 @@ HEADERS += \
     sources/pdfsignaturehandler.h \
     sources/pdfsignaturehandler_impl.h \
     sources/pdfsnapper.h \
+    sources/pdfstructuretree.h \
     sources/pdftextlayout.h \
     sources/pdfwidgettool.h \
     sources/pdfwidgetutils.h \
diff --git a/PdfForQtLib/sources/pdfcatalog.cpp b/PdfForQtLib/sources/pdfcatalog.cpp
index 529f628..bac845d 100644
--- a/PdfForQtLib/sources/pdfcatalog.cpp
+++ b/PdfForQtLib/sources/pdfcatalog.cpp
@@ -25,6 +25,20 @@
 namespace pdf
 {
 
+// Entries for "Info" entry in trailer dictionary
+static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_TITLE = "Title";
+static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_AUTHOR = "Author";
+static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_SUBJECT = "Subject";
+static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_KEYWORDS = "Keywords";
+static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_CREATOR = "Creator";
+static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_PRODUCER = "Producer";
+static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_CREATION_DATE = "CreationDate";
+static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_MODIFIED_DATE = "ModDate";
+static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_TRAPPED = "Trapped";
+static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_TRAPPED_TRUE = "True";
+static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_TRAPPED_FALSE = "False";
+static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_TRAPPED_UNKNOWN = "Unknown";
+
 static constexpr const char* PDF_VIEWER_PREFERENCES_DICTIONARY = "ViewerPreferences";
 static constexpr const char* PDF_VIEWER_PREFERENCES_HIDE_TOOLBAR = "HideToolbar";
 static constexpr const char* PDF_VIEWER_PREFERENCES_HIDE_MENUBAR = "HideMenubar";
@@ -133,6 +147,15 @@ PDFCatalog PDFCatalog::parse(const PDFObject& catalog, const PDFDocument* docume
         catalogObject.m_pageMode = loader.readEnumByName(catalogDictionary->get("PageMode"), pageModes.begin(), pageModes.end(), PageMode::UseNone);
     }
 
+    if (const PDFDictionary* actionDictionary = document->getDictionaryFromObject(catalogDictionary->get("AA")))
+    {
+        catalogObject.m_documentActions[WillClose] = PDFAction::parse(&document->getStorage(), actionDictionary->get("WC"));
+        catalogObject.m_documentActions[WillSave] = PDFAction::parse(&document->getStorage(), actionDictionary->get("WS"));
+        catalogObject.m_documentActions[DidSave] = PDFAction::parse(&document->getStorage(), actionDictionary->get("DS"));
+        catalogObject.m_documentActions[WillPrint] = PDFAction::parse(&document->getStorage(), actionDictionary->get("WP"));
+        catalogObject.m_documentActions[DidPrint] = PDFAction::parse(&document->getStorage(), actionDictionary->get("DP"));
+    }
+
     catalogObject.m_version = loader.readNameFromDictionary(catalogDictionary, "Version");
 
     if (const PDFDictionary* namesDictionary = document->getDictionaryFromObject(catalogDictionary->get("Names")))
@@ -172,6 +195,8 @@ PDFCatalog PDFCatalog::parse(const PDFObject& catalog, const PDFDocument* docume
     catalogObject.m_formObject = catalogDictionary->get("AcroForm");
     catalogObject.m_extensions = PDFDeveloperExtensions::parse(catalogDictionary->get("Extensions"), document);
     catalogObject.m_documentSecurityStore = PDFDocumentSecurityStore::parse(catalogDictionary->get("DSS"), document);
+    catalogObject.m_threads = loader.readObjectList<PDFArticleThread>(catalogDictionary->get("Threads"));
+    catalogObject.m_metadata = catalogDictionary->get("Metadata");
 
     return catalogObject;
 }
@@ -573,4 +598,163 @@ PDFDeveloperExtensions PDFDeveloperExtensions::parse(const PDFObject& object, co
     return extensions;
 }
 
+PDFDocumentInfo PDFDocumentInfo::parse(const PDFObject& object, const PDFObjectStorage* storage)
+{
+    PDFDocumentInfo info;
+
+    if (const PDFDictionary* infoDictionary = storage->getDictionaryFromObject(object))
+    {
+        auto readTextString = [storage, infoDictionary](const char* entry, QString& fillEntry)
+        {
+            if (infoDictionary->hasKey(entry))
+            {
+                const PDFObject& stringObject = storage->getObject(infoDictionary->get(entry));
+                if (stringObject.isString())
+                {
+                    // We have succesfully read the string, convert it according to encoding
+                    fillEntry = PDFEncoding::convertTextString(stringObject.getString());
+                }
+                else if (!stringObject.isNull())
+                {
+                    throw PDFException(PDFTranslationContext::tr("Bad format of document info entry in trailer dictionary. String expected."));
+                }
+            }
+        };
+        readTextString(PDF_DOCUMENT_INFO_ENTRY_TITLE, info.title);
+        readTextString(PDF_DOCUMENT_INFO_ENTRY_AUTHOR, info.author);
+        readTextString(PDF_DOCUMENT_INFO_ENTRY_SUBJECT, info.subject);
+        readTextString(PDF_DOCUMENT_INFO_ENTRY_KEYWORDS, info.keywords);
+        readTextString(PDF_DOCUMENT_INFO_ENTRY_CREATOR, info.creator);
+        readTextString(PDF_DOCUMENT_INFO_ENTRY_PRODUCER, info.producer);
+
+        auto readDate= [storage, infoDictionary](const char* entry, QDateTime& fillEntry)
+        {
+            if (infoDictionary->hasKey(entry))
+            {
+                const PDFObject& stringObject = storage->getObject(infoDictionary->get(entry));
+                if (stringObject.isString())
+                {
+                    // We have succesfully read the string, convert it to date time
+                    fillEntry = PDFEncoding::convertToDateTime(stringObject.getString());
+
+                    if (!fillEntry.isValid())
+                    {
+                        throw PDFException(PDFTranslationContext::tr("Bad format of document info entry in trailer dictionary. String with date time format expected."));
+                    }
+                }
+                else if (!stringObject.isNull())
+                {
+                    throw PDFException(PDFTranslationContext::tr("Bad format of document info entry in trailer dictionary. String with date time format expected."));
+                }
+            }
+        };
+        readDate(PDF_DOCUMENT_INFO_ENTRY_CREATION_DATE, info.creationDate);
+        readDate(PDF_DOCUMENT_INFO_ENTRY_MODIFIED_DATE, info.modifiedDate);
+
+        if (infoDictionary->hasKey(PDF_DOCUMENT_INFO_ENTRY_TRAPPED))
+        {
+            const PDFObject& nameObject = storage->getObject(infoDictionary->get(PDF_DOCUMENT_INFO_ENTRY_TRAPPED));
+            if (nameObject.isName())
+            {
+                const QByteArray& name = nameObject.getString();
+                if (name == PDF_DOCUMENT_INFO_ENTRY_TRAPPED_TRUE)
+                {
+                    info.trapped = Trapped::True;
+                }
+                else if (name == PDF_DOCUMENT_INFO_ENTRY_TRAPPED_FALSE)
+                {
+                    info.trapped = Trapped::False;
+                }
+                else if (name == PDF_DOCUMENT_INFO_ENTRY_TRAPPED_UNKNOWN)
+                {
+                    info.trapped = Trapped::Unknown;
+                }
+                else
+                {
+                    throw PDFException(PDFTranslationContext::tr("Bad format of document info entry in trailer dictionary. Trapping information expected"));
+                }
+            }
+            else if (nameObject.isBool())
+            {
+                info.trapped = nameObject.getBool() ? Trapped::True : Trapped::False;
+            }
+            else
+            {
+                throw PDFException(PDFTranslationContext::tr("Bad format of document info entry in trailer dictionary. Trapping information expected"));
+            }
+        }
+
+        // Scan for extra items
+        constexpr const char* PREDEFINED_ITEMS[] = { PDF_DOCUMENT_INFO_ENTRY_TITLE, PDF_DOCUMENT_INFO_ENTRY_AUTHOR, PDF_DOCUMENT_INFO_ENTRY_SUBJECT,
+                                                     PDF_DOCUMENT_INFO_ENTRY_KEYWORDS, PDF_DOCUMENT_INFO_ENTRY_CREATOR, PDF_DOCUMENT_INFO_ENTRY_PRODUCER,
+                                                     PDF_DOCUMENT_INFO_ENTRY_CREATION_DATE, PDF_DOCUMENT_INFO_ENTRY_MODIFIED_DATE, PDF_DOCUMENT_INFO_ENTRY_TRAPPED };
+        for (size_t i = 0; i < infoDictionary->getCount(); ++i)
+        {
+            QByteArray key = infoDictionary->getKey(i).getString();
+            if (std::none_of(std::begin(PREDEFINED_ITEMS), std::end(PREDEFINED_ITEMS), [&key](const char* item) { return item == key; }))
+            {
+                const PDFObject& value = storage->getObject(infoDictionary->getValue(i));
+                if (value.isString())
+                {
+                    const QByteArray& stringValue = value.getString();
+                    QDateTime dateTime = PDFEncoding::convertToDateTime(stringValue);
+                    if (dateTime.isValid())
+                    {
+                        info.extra[key] = dateTime;
+                    }
+                    else
+                    {
+                        info.extra[key] = PDFEncoding::convertTextString(stringValue);
+                    }
+                }
+            }
+        }
+    }
+
+    return info;
+}
+
+PDFArticleThread PDFArticleThread::parse(const PDFObjectStorage* storage, const PDFObject& object)
+{
+    PDFArticleThread result;
+
+    if (const PDFDictionary* dictionary = storage->getDictionaryFromObject(object))
+    {
+        PDFDocumentDataLoaderDecorator loader(storage);
+        PDFObjectReference firstBeadReference = loader.readReferenceFromDictionary(dictionary, "F");
+
+        std::set<PDFObjectReference> visitedBeads;
+        PDFObjectReference currentBead = firstBeadReference;
+
+        while (!visitedBeads.count(currentBead))
+        {
+            visitedBeads.insert(currentBead);
+
+            // Read bead
+            if (const PDFDictionary* beadDictionary = storage->getDictionaryFromObject(storage->getObjectByReference(currentBead)))
+            {
+                Bead bead;
+                bead.self = currentBead;
+                bead.thread = loader.readReferenceFromDictionary(beadDictionary, "T");
+                bead.next = loader.readReferenceFromDictionary(beadDictionary, "N");
+                bead.previous = loader.readReferenceFromDictionary(beadDictionary, "V");
+                bead.page = loader.readReferenceFromDictionary(beadDictionary, "P");
+                bead.rect = loader.readRectangle(beadDictionary->get("R"), QRectF());
+
+                currentBead = bead.next;
+                result.m_beads.push_back(bead);
+            }
+            else
+            {
+                // current bead will be the same, the cycle will break
+            }
+        }
+
+        result.m_information = PDFDocumentInfo::parse(dictionary->get("I"), storage);
+        result.m_metadata = loader.readReferenceFromDictionary(dictionary, "Metadata");
+    }
+
+    return result;
+}
+
 }   // namespace pdf
diff --git a/PdfForQtLib/sources/pdfcatalog.h b/PdfForQtLib/sources/pdfcatalog.h
index e3fe5dc..1bd587b 100644
--- a/PdfForQtLib/sources/pdfcatalog.h
+++ b/PdfForQtLib/sources/pdfcatalog.h
@@ -104,6 +104,39 @@ private:
     PDFInteger m_startNumber;
 };
 
+/// Info about the document. Title, Author, Keywords... It also stores "extra"
+/// values, which are in info dictionary. They can be either strings, or date
+/// time (QString or QDateTime).
+struct PDFDocumentInfo
+{
+    /// Indicates, that document was modified that it includes trapping information.
+    /// See PDF Reference 1.7, Section 10.10.5 "Trapping Support".
+    enum class Trapped
+    {
+        True,       ///< Fully trapped
+        False,      ///< Not yet trapped
+        Unknown     ///< Either unknown, or it has been trapped partly, not fully
+    };
+
+    /// Parses info from catalog dictionary. If object cannot be parsed, or error occurs,
+    /// then exception is thrown. This function may throw exceptions, if error occured.
+    /// \param object Object containing info dictionary
+    /// \param storage Storage of objects
+    static PDFDocumentInfo parse(const PDFObject& object, const PDFObjectStorage* storage);
+
+    QString title;
+    QString author;
+    QString subject;
+    QString keywords;
+    QString creator;
+    QString producer;
+    QDateTime creationDate;
+    QDateTime modifiedDate;
+    Trapped trapped = Trapped::Unknown;
+    PDFVersion version;
+    std::map<QByteArray, QVariant> extra;
+};
+
 class PDFViewerPreferences
 {
 public:
@@ -225,6 +258,40 @@ private:
     std::map<QByteArray, SecurityStoreItem> m_VRI;
 };
 
+/// Article thread. Each thread contains beads, which can be across multiple pages.
+class PDFArticleThread
+{
+public:
+    explicit inline PDFArticleThread() = default;
+
+    struct Bead
+    {
+        PDFObjectReference self;
+        PDFObjectReference thread;
+        PDFObjectReference next;
+        PDFObjectReference previous;
+        PDFObjectReference page;
+        QRectF rect;
+    };
+    using Beads = std::vector<Bead>;
+    using Information = PDFDocumentInfo;
+
+    const Beads& getBeads() const { return m_beads; }
+    const Information& getInformation() const { return m_information; }
+    const PDFObjectReference& getMetadata() const { return m_metadata; }
+
+    /// Parses article thread from object. If object cannot be parsed, or error occurs,
+    /// then empty object is returned.
+    /// \param storage Storage
+    /// \param object Object
+    static PDFArticleThread parse(const PDFObjectStorage* storage, const PDFObject& object);
+
+private:
+    Beads m_beads;
+    Information m_information;
+    PDFObjectReference m_metadata;
+};
+
 /// Document extensions. Contains information about developer's extensions
 /// used in document.
 class PDFFORQTLIBSHARED_EXPORT PDFDeveloperExtensions
@@ -268,6 +335,16 @@ public:
 
     static constexpr const size_t INVALID_PAGE_INDEX = std::numeric_limits<size_t>::max();
 
+    enum DocumentAction
+    {
+        WillClose,
+        WillSave,
+        DidSave,
+        WillPrint,
+        DidPrint,
+        LastDocumentAction
+    };
+
     /// Returns viewer preferences of the application
     const PDFViewerPreferences* getViewerPreferences() const { return &m_viewerPreferences; }
 
@@ -299,6 +376,9 @@ public:
     const PDFObject& getFormObject() const { return m_formObject; }
     const PDFDeveloperExtensions& getExtensions() const { return m_extensions; }
     const PDFDocumentSecurityStore& getDocumentSecurityStore() const { return m_documentSecurityStore; }
+    const std::vector<PDFArticleThread>& getArticleThreads() const { return m_threads; }
+    const PDFAction* getDocumentAction(DocumentAction action) const { return m_documentActions.at(action).get(); }
+    const PDFObject& getMetadata() const { return m_metadata; }
 
     /// Returns destination using the key. If destination with the key is not found,
     /// then nullptr is returned.
@@ -318,12 +398,15 @@ private:
     PDFOptionalContentProperties m_optionalContentProperties;
     QSharedPointer<PDFOutlineItem> m_outlineRoot;
     PDFActionPtr m_openAction;
+    std::array<PDFActionPtr, LastDocumentAction> m_documentActions;
     PageLayout m_pageLayout = PageLayout::SinglePage;
     PageMode m_pageMode = PageMode::UseNone;
     QByteArray m_baseURI;
     PDFObject m_formObject;
     PDFDeveloperExtensions m_extensions;
     PDFDocumentSecurityStore m_documentSecurityStore;
+    std::vector<PDFArticleThread> m_threads;
+    PDFObject m_metadata;
 
     // Maps from Names dictionary
     std::map<QByteArray, PDFDestination> m_destinations;
diff --git a/PdfForQtLib/sources/pdfdocument.cpp b/PdfForQtLib/sources/pdfdocument.cpp
index bdabb05..3dcaee0 100644
--- a/PdfForQtLib/sources/pdfdocument.cpp
+++ b/PdfForQtLib/sources/pdfdocument.cpp
@@ -25,20 +25,7 @@
 namespace pdf
 {
 
-// Entries for "Info" entry in trailer dictionary
 static constexpr const char* PDF_DOCUMENT_INFO_ENTRY = "Info";
-static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_TITLE = "Title";
-static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_AUTHOR = "Author";
-static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_SUBJECT = "Subject";
-static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_KEYWORDS = "Keywords";
-static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_CREATOR = "Creator";
-static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_PRODUCER = "Producer";
-static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_CREATION_DATE = "CreationDate";
-static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_MODIFIED_DATE = "ModDate";
-static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_TRAPPED = "Trapped";
-static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_TRAPPED_TRUE = "True";
-static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_TRAPPED_FALSE = "False";
-static constexpr const char* PDF_DOCUMENT_INFO_ENTRY_TRAPPED_UNKNOWN = "Unknown";
 
 QByteArray PDFObjectStorage::getDecodedStream(const PDFStream* stream) const
 {
@@ -110,123 +97,7 @@ void PDFDocument::initInfo()
 
     if (dictionary->hasKey(PDF_DOCUMENT_INFO_ENTRY))
     {
-        const PDFObject& info = getObject(dictionary->get(PDF_DOCUMENT_INFO_ENTRY));
-
-        if (info.isDictionary())
-        {
-            const PDFDictionary* infoDictionary = info.getDictionary();
-            Q_ASSERT(infoDictionary);
-
-            auto readTextString = [this, infoDictionary](const char* entry, QString& fillEntry)
-            {
-                if (infoDictionary->hasKey(entry))
-                {
-                    const PDFObject& stringObject = getObject(infoDictionary->get(entry));
-                    if (stringObject.isString())
-                    {
-                        // We have succesfully read the string, convert it according to encoding
-                        fillEntry = PDFEncoding::convertTextString(stringObject.getString());
-                    }
-                    else if (!stringObject.isNull())
-                    {
-                        throw PDFException(tr("Bad format of document info entry in trailer dictionary. String expected."));
-                    }
-                }
-            };
-            readTextString(PDF_DOCUMENT_INFO_ENTRY_TITLE, m_info.title);
-            readTextString(PDF_DOCUMENT_INFO_ENTRY_AUTHOR, m_info.author);
-            readTextString(PDF_DOCUMENT_INFO_ENTRY_SUBJECT, m_info.subject);
-            readTextString(PDF_DOCUMENT_INFO_ENTRY_KEYWORDS, m_info.keywords);
-            readTextString(PDF_DOCUMENT_INFO_ENTRY_CREATOR, m_info.creator);
-            readTextString(PDF_DOCUMENT_INFO_ENTRY_PRODUCER, m_info.producer);
-
-            auto readDate= [this, infoDictionary](const char* entry, QDateTime& fillEntry)
-            {
-                if (infoDictionary->hasKey(entry))
-                {
-                    const PDFObject& stringObject = getObject(infoDictionary->get(entry));
-                    if (stringObject.isString())
-                    {
-                        // We have succesfully read the string, convert it to date time
-                        fillEntry = PDFEncoding::convertToDateTime(stringObject.getString());
-
-                        if (!fillEntry.isValid())
-                        {
-                            throw PDFException(tr("Bad format of document info entry in trailer dictionary. String with date time format expected."));
-                        }
-                    }
-                    else if (!stringObject.isNull())
-                    {
-                        throw PDFException(tr("Bad format of document info entry in trailer dictionary. String with date time format expected."));
-                    }
-                }
-            };
-            readDate(PDF_DOCUMENT_INFO_ENTRY_CREATION_DATE, m_info.creationDate);
-            readDate(PDF_DOCUMENT_INFO_ENTRY_MODIFIED_DATE, m_info.modifiedDate);
-
-            if (infoDictionary->hasKey(PDF_DOCUMENT_INFO_ENTRY_TRAPPED))
-            {
-                const PDFObject& nameObject = getObject(infoDictionary->get(PDF_DOCUMENT_INFO_ENTRY_TRAPPED));
-                if (nameObject.isName())
-                {
-                    const QByteArray& name = nameObject.getString();
-                    if (name == PDF_DOCUMENT_INFO_ENTRY_TRAPPED_TRUE)
-                    {
-                        m_info.trapped = Info::Trapped::True;
-                    }
-                    else if (name == PDF_DOCUMENT_INFO_ENTRY_TRAPPED_FALSE)
-                    {
-                        m_info.trapped = Info::Trapped::False;
-                    }
-                    else if (name == PDF_DOCUMENT_INFO_ENTRY_TRAPPED_UNKNOWN)
-                    {
-                        m_info.trapped = Info::Trapped::Unknown;
-                    }
-                    else
-                    {
-                        throw PDFException(tr("Bad format of document info entry in trailer dictionary. Trapping information expected"));
-                    }
-                }
-                else if (nameObject.isBool())
-                {
-                    m_info.trapped = nameObject.getBool() ? Info::Trapped::True : Info::Trapped::False;
-                }
-                else
-                {
-                    throw PDFException(tr("Bad format of document info entry in trailer dictionary. Trapping information expected"));
-                }
-            }
-
-            // Scan for extra items
-            constexpr const char* PREDEFINED_ITEMS[] = { PDF_DOCUMENT_INFO_ENTRY_TITLE, PDF_DOCUMENT_INFO_ENTRY_AUTHOR, PDF_DOCUMENT_INFO_ENTRY_SUBJECT,
-                                                         PDF_DOCUMENT_INFO_ENTRY_KEYWORDS, PDF_DOCUMENT_INFO_ENTRY_CREATOR, PDF_DOCUMENT_INFO_ENTRY_PRODUCER,
-                                                         PDF_DOCUMENT_INFO_ENTRY_CREATION_DATE, PDF_DOCUMENT_INFO_ENTRY_MODIFIED_DATE, PDF_DOCUMENT_INFO_ENTRY_TRAPPED };
-            for (size_t i = 0; i < infoDictionary->getCount(); ++i)
-            {
-                QByteArray key = infoDictionary->getKey(i).getString();
-                if (std::none_of(std::begin(PREDEFINED_ITEMS), std::end(PREDEFINED_ITEMS), [&key](const char* item) { return item == key; }))
-                {
-                    const PDFObject& value = getObject(infoDictionary->getValue(i));
-                    if (value.isString())
-                    {
-                        const QByteArray& stringValue = value.getString();
-                        QDateTime dateTime = PDFEncoding::convertToDateTime(stringValue);
-                        if (dateTime.isValid())
-                        {
-                            m_info.extra[key] = dateTime;
-                        }
-                        else
-                        {
-                            m_info.extra[key] = PDFEncoding::convertTextString(stringValue);
-                        }
-                    }
-                }
-            }
-        }
-        else if (!info.isNull()) // Info may be invalid...
-        {
-            throw PDFException(tr("Bad format of document info entry in trailer dictionary."));
-        }
+        m_info = PDFDocumentInfo::parse(dictionary->get(PDF_DOCUMENT_INFO_ENTRY), &m_pdfObjectStorage);
     }
 }
 
diff --git a/PdfForQtLib/sources/pdfdocument.h b/PdfForQtLib/sources/pdfdocument.h
index ecbae32..e087352 100644
--- a/PdfForQtLib/sources/pdfdocument.h
+++ b/PdfForQtLib/sources/pdfdocument.h
@@ -408,35 +408,8 @@ public:
 
     const PDFObjectStorage& getStorage() const { return m_pdfObjectStorage; }
 
-    /// Info about the document. Title, Author, Keywords... It also stores "extra"
-    /// values, which are in info dictionary. They can be either strings, or date
-    /// time (QString or QDateTime).
-    struct Info
-    {
-        /// Indicates, that document was modified that it includes trapping information.
-        /// See PDF Reference 1.7, Section 10.10.5 "Trapping Support".
-        enum class Trapped
-        {
-            True,       ///< Fully trapped
-            False,      ///< Not yet trapped
-            Unknown     ///< Either unknown, or it has been trapped partly, not fully
-        };
-
-        QString title;
-        QString author;
-        QString subject;
-        QString keywords;
-        QString creator;
-        QString producer;
-        QDateTime creationDate;
-        QDateTime modifiedDate;
-        Trapped trapped = Trapped::Unknown;
-        PDFVersion version;
-        std::map<QByteArray, QVariant> extra;
-    };
-
     /// Returns info about the document (title, author, etc.)
-    const Info* getInfo() const { return &m_info; }
+    const PDFDocumentInfo* getInfo() const { return &m_info; }
 
     /// If object is reference, the dereference attempt is performed
     /// and object is returned. If it is not a reference, then self
@@ -494,7 +467,7 @@ private:
     PDFObjectStorage m_pdfObjectStorage;
 
     /// Info about the PDF document
-    Info m_info;
+    PDFDocumentInfo m_info;
 
     /// Catalog object
     PDFCatalog m_catalog;
diff --git a/PdfForQtLib/sources/pdfstructuretree.cpp b/PdfForQtLib/sources/pdfstructuretree.cpp
new file mode 100644
index 0000000..b0a2a89
--- /dev/null
+++ b/PdfForQtLib/sources/pdfstructuretree.cpp
@@ -0,0 +1,163 @@
+//    Copyright (C) 2019-2020 Jakub Melka
+//
+//    This file is part of PdfForQt.
+//
+//    PdfForQt is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU Lesser General Public License as published by
+//    the Free Software Foundation, either version 3 of the License, or
+//    (at your option) any later version.
+//
+//    PdfForQt is distributed in the hope that it will be useful,
+//    but WITHOUT ANY WARRANTY; without even the implied warranty of
+//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//    GNU Lesser General Public License for more details.
+//
+//    You should have received a copy of the GNU Lesser General Public License
+//    along with PDFForQt.  If not, see <https://www.gnu.org/licenses/>.
+
+#include "pdfstructuretree.h"
+
+#include <array>
+
+namespace pdf
+{
+
+/// Attribute definition structure
+struct PDFStructureTreeAttributeDefinition
+{
+    constexpr inline PDFStructureTreeAttributeDefinition() = default;
+    constexpr inline PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute type,
+                                                         const char* name,
+                                                         bool inheritable) :
+        type(type),
+        name(name),
+        inheritable(inheritable)
+    {
+
+    }
+
+    /// Returns attribute definition for given attribute name. This function
+    /// always returns valid pointer. For uknown attribute, it returns
+    /// user attribute definition.
+    /// \param name Attribute name
+    const PDFStructureTreeAttributeDefinition* getDefinition(const QByteArray& name);
+
+    PDFStructureTreeAttribute::Owner getOwnerFromString(const QByteArray& string);
+
+    PDFStructureTreeAttribute::Attribute type = PDFStructureTreeAttribute::Attribute::User;
+    const char* name = nullptr;
+    bool inheritable = false;
+};
+
+
+static constexpr std::array<std::pair<const char*, const PDFStructureTreeAttribute::Owner>, 16> s_ownerDefinitions =
+{
+    std::pair<const char*, const PDFStructureTreeAttribute::Owner>("Layout", PDFStructureTreeAttribute::Owner::Layout),
+    std::pair<const char*, const PDFStructureTreeAttribute::Owner>("List", PDFStructureTreeAttribute::Owner::List),
+    std::pair<const char*, const PDFStructureTreeAttribute::Owner>("PrintField", PDFStructureTreeAttribute::Owner::PrintField),
+    std::pair<const char*, const PDFStructureTreeAttribute::Owner>("Table", PDFStructureTreeAttribute::Owner::Table),
+    std::pair<const char*, const PDFStructureTreeAttribute::Owner>("Artifact", PDFStructureTreeAttribute::Owner::Artifact),
+    std::pair<const char*, const PDFStructureTreeAttribute::Owner>("XML-1.00", PDFStructureTreeAttribute::Owner::XML_1_00),
+    std::pair<const char*, const PDFStructureTreeAttribute::Owner>("HTML-3.20", PDFStructureTreeAttribute::Owner::HTML_3_20),
+    std::pair<const char*, const PDFStructureTreeAttribute::Owner>("HTML-4.01", PDFStructureTreeAttribute::Owner::HTML_4_01),
+    std::pair<const char*, const PDFStructureTreeAttribute::Owner>("HTML-5.00", PDFStructureTreeAttribute::Owner::HTML_5_00),
+    std::pair<const char*, const PDFStructureTreeAttribute::Owner>("OEB-1.00", PDFStructureTreeAttribute::Owner::OEB_1_00),
+    std::pair<const char*, const PDFStructureTreeAttribute::Owner>("RTF-1.05", PDFStructureTreeAttribute::Owner::RTF_1_05),
+    std::pair<const char*, const PDFStructureTreeAttribute::Owner>("CSS-1.00", PDFStructureTreeAttribute::Owner::CSS_1_00),
+    std::pair<const char*, const PDFStructureTreeAttribute::Owner>("CSS-2.00", PDFStructureTreeAttribute::Owner::CSS_2_00),
+    std::pair<const char*, const PDFStructureTreeAttribute::Owner>("CSS-3.00", PDFStructureTreeAttribute::Owner::CSS_3_00),
+    std::pair<const char*, const PDFStructureTreeAttribute::Owner>("RDFa-1.10", PDFStructureTreeAttribute::Owner::RDFa_1_10),
+    std::pair<const char*, const PDFStructureTreeAttribute::Owner>("ARIA-1.1", PDFStructureTreeAttribute::Owner::ARIA_1_1)
+};
+
+static constexpr std::array<const PDFStructureTreeAttributeDefinition, PDFStructureTreeAttribute::Attribute::LastAttribute + 1> s_attributeDefinitions =
+{
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::User, "", false), // User
+
+    // Standard layout attributes
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::Placement, "Placement", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::WritingMode, "WritingMode", true),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::BackgroundColor, "BackgroundColor", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::BorderColor, "BorderColor", true),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::BorderStyle, "BorderStyle", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::BorderThickness, "BorderThickness", true),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::Color, "Color", true),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::Padding, "Padding", false),
+
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::SpaceBefore, "SpaceBefore", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::SpaceAfter, "SpaceAfter", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::StartIndent, "StartIndent", true),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::EndIndent, "EndIndent", true),
+
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::TextIndent, "TextIndent", true),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::TextAlign, "TextAlign", true),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::BBox, "BBox", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::Width, "Width", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::Height, "Height", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::BlockAlign, "BlockAlign", true),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::InlineAlign, "InlineAlign", true),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::TBorderStyle, "TBorderStyle", true),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::TPadding, "TPadding", true),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::LineHeight, "LineHeight", true),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::BaselineShift, "BaselineShift", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::TextDecorationType, "TextDecorationType", true),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::TextDecorationColor, "TextDecorationColor", true),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::TextDecorationThickness, "TextDecorationThickness", true),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::ColumnCount, "ColumnCount", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::ColumnWidths, "ColumnWidths", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::ColumnGap, "ColumnGap", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::GlyphOrientationVertical, "GlyphOrientationVertical", true),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::RubyAlign, "RubyAlign", true),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::RubyPosition, "RubyPosition", true),
+
+    // List attributes
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::ListNumbering, "ListNumbering", true),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::ContinuedList, "ContinuedList", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::ContinuedFrom, "ContinuedFrom", false),
+
+    // PrintField attributes
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::Role, "Role", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::Checked, "Checked", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::Checked, "checked", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::Desc, "Desc", false),
+
+    // Table attributes
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::RowSpan, "RowSpan", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::ColSpan, "ColSpan", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::Headers, "Headers", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::Scope, "Scope", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::Short, "Short", false),
+
+    // Artifact attributes
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::Type, "Type", false),
+    PDFStructureTreeAttributeDefinition(PDFStructureTreeAttribute::Attribute::Subtype, "Subtype", false)
+};
+
+const PDFStructureTreeAttributeDefinition* PDFStructureTreeAttributeDefinition::getDefinition(const QByteArray& name)
+{
+    for (const PDFStructureTreeAttributeDefinition& definition : s_attributeDefinitions)
+    {
+        if (name == definition.name)
+        {
+            return &definition;
+        }
+    }
+
+    Q_ASSERT(s_attributeDefinitions.front().type == PDFStructureTreeAttribute::Attribute::User);
+    return &s_attributeDefinitions.front();
+}
+
+PDFStructureTreeAttribute::Owner PDFStructureTreeAttributeDefinition::getOwnerFromString(const QByteArray& string)
+{
+    for (const auto& item : s_ownerDefinitions)
+    {
+        if (string == item.first)
+        {
+            return item.second;
+        }
+    }
+
+    return PDFStructureTreeAttribute::Owner::User;
+}
+
+}   // namespace pdf
diff --git a/PdfForQtLib/sources/pdfstructuretree.h b/PdfForQtLib/sources/pdfstructuretree.h
new file mode 100644
index 0000000..57cf765
--- /dev/null
+++ b/PdfForQtLib/sources/pdfstructuretree.h
@@ -0,0 +1,132 @@
+//    Copyright (C) 2019-2020 Jakub Melka
+//
+//    This file is part of PdfForQt.
+//
+//    PdfForQt is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU Lesser General Public License as published by
+//    the Free Software Foundation, either version 3 of the License, or
+//    (at your option) any later version.
+//
+//    PdfForQt is distributed in the hope that it will be useful,
+//    but WITHOUT ANY WARRANTY; without even the implied warranty of
+//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//    GNU Lesser General Public License for more details.
+//
+//    You should have received a copy of the GNU Lesser General Public License
+//    along with PDFForQt.  If not, see <https://www.gnu.org/licenses/>.
+
+#ifndef PDFSTRUCTURETREE_H
+#define PDFSTRUCTURETREE_H
+
+#include "pdfobject.h"
+
+namespace pdf
+{
+
+struct PDFStructureTreeAttributeDefinition;
+
+class PDFStructureTreeAttribute
+{
+public:
+
+    enum class Owner
+    {
+        /// Defined for user owner
+        User,
+
+        Layout,
+        List,
+        PrintField,
+        Table,
+
+        Artifact,
+
+        XML_1_00,
+        HTML_3_20,
+        HTML_4_01,
+        HTML_5_00,
+        OEB_1_00,
+        RTF_1_05,
+        CSS_1_00,
+        CSS_2_00,
+        CSS_3_00,
+        RDFa_1_10,
+        ARIA_1_1,
+    };
+
+    enum Attribute
+    {
+        User,
+
+        // Standard layout attributes
+        Placement,
+        WritingMode,
+        BackgroundColor,
+        BorderColor,
+        BorderStyle,
+        BorderThickness,
+        Color,
+        Padding,
+
+        // Block element attributes
+        SpaceBefore,
+        SpaceAfter,
+        StartIndent,
+        EndIndent,
+        TextIndent,
+        TextAlign,
+        BBox,
+        Width,
+        Height,
+        BlockAlign,
+        InlineAlign,
+        TBorderStyle,
+        TPadding,
+        LineHeight,
+        BaselineShift,
+        TextDecorationType,
+        TextDecorationColor,
+        TextDecorationThickness,
+        ColumnCount,
+        ColumnWidths,
+        ColumnGap,
+        GlyphOrientationVertical,
+        RubyAlign,
+        RubyPosition,
+
+        // List attributes
+        ListNumbering,
+        ContinuedList,
+        ContinuedFrom,
+
+        // PrintField attributes
+        Role,
+        Checked,
+        Desc,
+
+        // Table attributes
+        RowSpan,
+        ColSpan,
+        Headers,
+        Scope,
+        Short,
+
+        // Artifact attributes
+        Type,
+        Subtype,
+
+        LastAttribute
+    };
+
+private:
+};
+
+class PDFStructureTree
+{
+public:
+    PDFStructureTree();
+};
+
+}   // namespace pdf
+
+#endif // PDFSTRUCTURETREE_H
diff --git a/PdfForQtViewer/pdfdocumentpropertiesdialog.cpp b/PdfForQtViewer/pdfdocumentpropertiesdialog.cpp
index bcce0fe..376a3f4 100644
--- a/PdfForQtViewer/pdfdocumentpropertiesdialog.cpp
+++ b/PdfForQtViewer/pdfdocumentpropertiesdialog.cpp
@@ -70,7 +70,7 @@ void PDFDocumentPropertiesDialog::initializeProperties(const pdf::PDFDocument* d
     // Initialize document properties
     QTreeWidgetItem* propertiesRoot = new QTreeWidgetItem({ tr("Properties") });
 
-    const pdf::PDFDocument::Info* info = document->getInfo();
+    const pdf::PDFDocumentInfo* info = document->getInfo();
     const pdf::PDFCatalog* catalog = document->getCatalog();
     new QTreeWidgetItem(propertiesRoot, { tr("PDF version"), QString::fromLatin1(document->getVersion()) });
     new QTreeWidgetItem(propertiesRoot, { tr("Title"), info->title });
@@ -85,15 +85,15 @@ void PDFDocumentPropertiesDialog::initializeProperties(const pdf::PDFDocument* d
     QString trapped;
     switch (info->trapped)
     {
-        case pdf::PDFDocument::Info::Trapped::True:
+        case pdf::PDFDocumentInfo::Trapped::True:
             trapped = tr("True");
             break;
 
-        case pdf::PDFDocument::Info::Trapped::False:
+        case pdf::PDFDocumentInfo::Trapped::False:
             trapped = tr("False");
             break;
 
-        case pdf::PDFDocument::Info::Trapped::Unknown:
+        case pdf::PDFDocumentInfo::Trapped::Unknown:
             trapped = tr("Unknown");
             break;