diff --git a/src/addressee.h b/src/addressee.h
--- a/src/addressee.h
+++ b/src/addressee.h
@@ -1059,6 +1059,97 @@
     void setClientPidMapList(const ClientPidMap::List &clientpidmaplist);
     void insertClientPidMap(const ClientPidMap &clientpidmap);
 
+    /**
+     * Returns the contact's anniversary date.
+     * @note This is a non-standard extension using the @c X-Anniversary field.
+     * @since 5.12
+     */
+    QDate anniversary() const;
+    /**
+     * Sets the contact's anniversary date.
+     * @note This is a non-standard extension using the @c X-Anniversary field.
+     * @since 5.12
+     */
+    void setAnniversary(const QDate &anniversary);
+
+    /**
+     * Returns the contact's assistant's name.
+     * @note This is a non-standard extension using the @c X-AssistantsName field.
+     * @since 5.12
+     */
+    QString assistantsName() const;
+    /**
+     * Set the contact's assistant's name.
+     * @note This is a non-standard extension using the @c X-AssistantsName field.
+     * @since 5.12
+     */
+    void setAssistantsName(const QString &assistantsName);
+
+    /**
+     * Returns the contact's blog feed.
+     * @note This is a non-standard extension using the @c BlogFeed field.
+     * @since 5.12
+     */
+    QString blogFeed() const;
+    /**
+     * Set the contact's blog feed.
+     * @note This is a non-standard extension using the @c BlogFeed field.
+     * @since 5.12
+     */
+    void setBlogFeed(const QString &blogFeed);
+
+    /**
+     * Returns the contact's manager's name.
+     * @note This is a non-standard extension using the @c X-ManagersName field.
+     * @since 5.12
+     */
+    QString managersName() const;
+    /**
+     * Set the contact's manager's name.
+     * @note This is a non-standard extension using the @c X-ManagersName field.
+     * @since 5.12
+     */
+    void setManagersName(const QString &managersName);
+
+    /**
+     * Returns the contact's office.
+     * @note This is a non-standard extension using the @c X-Office field.
+     * @since 5.12
+     */
+    QString office() const;
+    /**
+     * Set the contact's office.
+     * @note This is a non-standard extension using the @c X-Office field.
+     * @since 5.12
+     */
+    void setOffice(const QString &office);
+
+    /**
+     * Returns the contact's profession.
+     * @note This is a non-standard extension using the @c X-Profession field.
+     * @since 5.12
+     */
+    QString profession() const;
+    /**
+     * Set the contact's profession.
+     * @note This is a non-standard extension using the @c X-Profession field.
+     * @since 5.12
+     */
+    void setProfession(const QString &profession);
+
+    /**
+     * Returns the contact's spouse's name.
+     * @note This is a non-standard extension using the @c X-SpousesName field.
+     * @since 5.12
+     */
+    QString spousesName() const;
+    /**
+     * Set the contact's spouse's name.
+     * @note This is a non-standard extension using the @c X-SpousesName field.
+     * @since 5.12
+     */
+    void setSpousesName(const QString &spousesName);
+
 private:
     class Private;
     QSharedDataPointer<Private> d;
diff --git a/src/addressee.cpp b/src/addressee.cpp
--- a/src/addressee.cpp
+++ b/src/addressee.cpp
@@ -20,6 +20,7 @@
     Boston, MA 02110-1301, USA.
 */
 
+#include <QDate>
 #include <QList>
 #include <QRegExp>
 #include <QSharedData>
@@ -2147,6 +2148,113 @@
     return d->mRelationShips;
 }
 
+static const auto VENDOR_ID = QStringLiteral("KADDRESSBOOK");
+static const auto X_ANNIVERSARY = QStringLiteral("X-Anniversary");
+static const auto X_ASSISTANTSNAME = QStringLiteral("X-AssistantsName");
+static const auto BLOGFEED = QStringLiteral("BlogFeed");
+static const auto X_MANAGERSNAME = QStringLiteral("X-ManagersName");
+static const auto X_OFFICE = QStringLiteral("X-Office");
+static const auto X_PROFESSION = QStringLiteral("X-Profession");
+static const auto X_SPOUSESNAME = QStringLiteral("X-SpousesName");
+
+QDate Addressee::anniversary() const
+{
+    return QDate::fromString(custom(VENDOR_ID, X_ANNIVERSARY), Qt::ISODate);
+}
+
+void Addressee::setAnniversary(const QDate &anniversary)
+{
+    if (anniversary.isValid()) {
+        insertCustom(VENDOR_ID, X_ANNIVERSARY, anniversary.toString(Qt::ISODate));
+    } else {
+        removeCustom(VENDOR_ID, X_ANNIVERSARY);
+    }
+}
+
+QString Addressee::assistantsName() const
+{
+    return custom(VENDOR_ID, X_ASSISTANTSNAME);
+}
+
+void Addressee::setAssistantsName(const QString &assistantsName)
+{
+    if (!assistantsName.isEmpty()) {
+        insertCustom(VENDOR_ID, X_ASSISTANTSNAME, assistantsName);
+    } else {
+        removeCustom(VENDOR_ID, X_ASSISTANTSNAME);
+    }
+}
+
+QString Addressee::blogFeed() const
+{
+    return custom(VENDOR_ID, BLOGFEED);
+}
+
+void Addressee::setBlogFeed(const QString &blogFeed)
+{
+    if (!blogFeed.isEmpty()) {
+        insertCustom(VENDOR_ID, BLOGFEED, blogFeed);
+    } else {
+        removeCustom(VENDOR_ID, BLOGFEED);
+    }
+}
+
+QString Addressee::managersName() const
+{
+    return custom(VENDOR_ID, X_MANAGERSNAME);
+}
+
+void Addressee::setManagersName(const QString &managersName)
+{
+    if (!managersName.isEmpty()) {
+        insertCustom(VENDOR_ID, X_MANAGERSNAME, managersName);
+    } else {
+        removeCustom(VENDOR_ID, X_MANAGERSNAME);
+    }
+}
+
+QString Addressee::office() const
+{
+    return custom(VENDOR_ID, X_OFFICE);
+}
+
+void Addressee::setOffice(const QString &office)
+{
+    if (!office.isEmpty()) {
+        insertCustom(VENDOR_ID, X_OFFICE, office);
+    } else {
+        removeCustom(VENDOR_ID, X_OFFICE);
+    }
+}
+
+QString Addressee::profession() const
+{
+    return custom(VENDOR_ID, X_PROFESSION);
+}
+
+void Addressee::setProfession(const QString &profession)
+{
+    if (!profession.isEmpty()) {
+        insertCustom(VENDOR_ID, X_PROFESSION, profession);
+    } else {
+        removeCustom(VENDOR_ID, X_PROFESSION);
+    }
+}
+
+QString Addressee::spousesName() const
+{
+    return custom(VENDOR_ID, X_SPOUSESNAME);
+}
+
+void Addressee::setSpousesName(const QString &spousesName)
+{
+    if (!spousesName.isEmpty()) {
+        insertCustom(VENDOR_ID, X_SPOUSESNAME, spousesName);
+    } else {
+        removeCustom(VENDOR_ID, X_SPOUSESNAME);
+    }
+}
+
 void Addressee::insertCustom(const QString &app, const QString &name, const QString &value)
 {
     if (value.isEmpty() || name.isEmpty() || app.isEmpty()) {