diff --git a/src/barchart/qbarseries.h b/src/barchart/qbarseries.h
index 2f7a6f1..b803690 100644
--- a/src/barchart/qbarseries.h
+++ b/src/barchart/qbarseries.h
@@ -55,6 +55,9 @@ public:
     QBarCategories categories() const;
 
     void setLabelsVisible(bool visible = true);
+// TODO:
+//    void setGroupedDrawing(bool on = true);   // By default this is on. Bars are grouped next to each other. If off, bars are drawn at their x-position (propably on top of each other)
+//    void setBarMargin(int margin);            // Margin that is left between bars (if drawn as grouped bars)
 
     bool setModel(QAbstractItemModel *model);
     void setModelMapping(int categories, int bottomBoundary, int topBoundary, Qt::Orientation orientation = Qt::Vertical);
diff --git a/src/barchart/qbarset.h b/src/barchart/qbarset.h
index 135c21a..210e071 100644
--- a/src/barchart/qbarset.h
+++ b/src/barchart/qbarset.h
@@ -39,10 +39,21 @@ public:
 
     void setName(const QString name);
     QString name() const;
-    void append(const qreal value);
-    QBarSet& operator << (const qreal &value);
-    void insert(const int index, const qreal value);
-    void remove(const int index);
+
+// TODO:
+//    void append(const QPointF value);         // Appends bar with x-value
+//    void append(const QList<QPointF> value);  // Same with list
+    void append(const qreal value);             // TODO: change so, that count becomes x-value
+
+// TODO:
+//    void append(const QList<qreal> values);   // Append list of values. Using index as x-value
+
+    QBarSet& operator << (const qreal &value);  // TODO: change implementations so, that count becomes x-value
+// TODO:
+//    QBarSet& operator << (const QPointF &value);  // Appends bar with x-value
+
+    void insert(const int index, const qreal value); // TODO: internal reindexing (what happens, if there are points with real x values?)
+    void remove(const int index);                    // TODO: internal reindexing (what happens, if there are points with real x values?)
     void replace(const int index, const qreal value);
     qreal at(const int index) const;
     qreal operator [] (int index) const;