diff --git a/GUI/coregui/Models/FTDistributionItems.cpp b/GUI/coregui/Models/FTDistributionItems.cpp
index f9236ede67ff5988e1eaf5e74fc2008a43f7b201..e1db15d81a6e9c0a90c42fd1ea2d0629a9762ab4 100644
--- a/GUI/coregui/Models/FTDistributionItems.cpp
+++ b/GUI/coregui/Models/FTDistributionItems.cpp
@@ -124,11 +124,8 @@ std::unique_ptr<IFTDistribution1D> FTDistribution1DVoigtItem::createFTDistributi
 
 // --------------------------------------------------------------------------------------------- //
 
-// TODO BACKCOMPATIBILITY (fix when we will break back compatibility)
-// Make P_OMEGA_X, P_OMEGA_Y depend on BornAgain::OmegaX and OmegaY
-
-const QString FTDistribution2DItem::P_OMEGA_X = "CoherenceLengthX"; // temp FIXME
-const QString FTDistribution2DItem::P_OMEGA_Y = "CoherenceLengthY"; // temp FIXME
+const QString FTDistribution2DItem::P_OMEGA_X = QString::fromStdString(BornAgain::OmegaX);
+const QString FTDistribution2DItem::P_OMEGA_Y = QString::fromStdString(BornAgain::OmegaY);
 const QString FTDistribution2DItem::P_GAMMA = QString::fromStdString(BornAgain::Gamma);
 
 FTDistribution2DItem::FTDistribution2DItem(const QString& name)
@@ -138,14 +135,10 @@ FTDistribution2DItem::FTDistribution2DItem(const QString& name)
 
 void FTDistribution2DItem::add_omega_properties()
 {
-    // TODO BACKCOMPATIBILITY (remove setDisplayName when P_OMEGA_X will be "OmegaX")
     addProperty(P_OMEGA_X, 1.0)->setToolTip(
-        QStringLiteral("Half-width of the distribution along its x-axis in nanometers"))
-            .setDisplayName("OmegaX");
-
+        QStringLiteral("Half-width of the distribution along its x-axis in nanometers"));
     addProperty(P_OMEGA_Y, 1.0)->setToolTip(
-        QStringLiteral("Half-width of the distribution along its y-axis in nanometers"))
-            .setDisplayName("OmegaY");
+        QStringLiteral("Half-width of the distribution along its y-axis in nanometers"));
 }
 
 void FTDistribution2DItem::add_gamma_property()
diff --git a/GUI/coregui/Models/FTDistributionItems.h b/GUI/coregui/Models/FTDistributionItems.h
index 4c63ded3d5b87e0f29af216adb665cce4ba48c22..ed07faf4c3f941d4d5b31ce72a0b29b35360cc84 100644
--- a/GUI/coregui/Models/FTDistributionItems.h
+++ b/GUI/coregui/Models/FTDistributionItems.h
@@ -85,7 +85,6 @@ public:
     static const QString P_GAMMA;
     explicit FTDistribution2DItem(const QString& name);
     virtual std::unique_ptr<IFTDistribution2D> createFTDistribution() const=0;
-    virtual ~FTDistribution2DItem(){}
 protected:
     void add_omega_properties();
     void add_gamma_property();
diff --git a/GUI/coregui/Models/InterferenceFunctionItems.cpp b/GUI/coregui/Models/InterferenceFunctionItems.cpp
index 459a4e05f65f7304b132a2fd1bc886b243ba9cbe..138b88534f08b13203e05c93d809390c65ddd47b 100644
--- a/GUI/coregui/Models/InterferenceFunctionItems.cpp
+++ b/GUI/coregui/Models/InterferenceFunctionItems.cpp
@@ -29,6 +29,10 @@
 #include "InterferenceFunction1DLattice.h"
 #include "GroupItem.h"
 
+namespace {
+    const QString decay_function_tag = "Decay Function";
+}
+
 // TODO (when back compatibility will be broken  again)
 // Make InterferenceFunction1DLatticeItem::P_DECAY_FUNCTION and
 // InterferenceFunction2DLatticeItem::P_DECAY_FUNCTION rely on same constant
@@ -200,7 +204,7 @@ const QString InterferenceFunction1DLatticeItem::P_LENGTH =
         QString::fromStdString(BornAgain::Length);
 const QString InterferenceFunction1DLatticeItem::P_ROTATION_ANGLE =
         QString::fromStdString(BornAgain::Xi);
-const QString InterferenceFunction1DLatticeItem::P_DECAY_FUNCTION = "Decay Function";
+const QString InterferenceFunction1DLatticeItem::P_DECAY_FUNCTION = decay_function_tag;
 
 InterferenceFunction1DLatticeItem::InterferenceFunction1DLatticeItem()
     : InterferenceFunctionItem(Constants::InterferenceFunction1DLatticeType)
@@ -230,7 +234,7 @@ InterferenceFunction1DLatticeItem::createInterferenceFunction() const
 // --------------------------------------------------------------------------------------------- //
 
 const QString InterferenceFunction2DLatticeItem::P_LATTICE_TYPE = "LatticeType";
-const QString InterferenceFunction2DLatticeItem::P_DECAY_FUNCTION = "DecayFunction";
+const QString InterferenceFunction2DLatticeItem::P_DECAY_FUNCTION = decay_function_tag;
 const QString InterferenceFunction2DLatticeItem::P_XI_INTEGRATION = "Integration_over_xi";
 
 InterferenceFunction2DLatticeItem::InterferenceFunction2DLatticeItem()
diff --git a/GUI/coregui/Models/SessionModelDelegate.cpp b/GUI/coregui/Models/SessionModelDelegate.cpp
index 5826b21be2a3ae243ba3767c79bc532915e93e5d..87f27f2f976f0071b05349c2c2f63f4748512223 100644
--- a/GUI/coregui/Models/SessionModelDelegate.cpp
+++ b/GUI/coregui/Models/SessionModelDelegate.cpp
@@ -30,7 +30,6 @@ bool isDoubleProperty(const QModelIndex& index)
 }
 
 //! Returns text representation of double value depending on user defined editor type.
-//! FIXME Remove this temporary function after getting rid from ScientificDoubleProperty
 QString doubleToString(const SessionItem& item)
 {
     QString result;