diff --git a/applications/utilities/mesh/conversion/foamMeshToFluent/fluentFvMesh.C b/applications/utilities/mesh/conversion/foamMeshToFluent/fluentFvMesh.C
index 6d45fdb56c..74a420aafc 100644
--- a/applications/utilities/mesh/conversion/foamMeshToFluent/fluentFvMesh.C
+++ b/applications/utilities/mesh/conversion/foamMeshToFluent/fluentFvMesh.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2018 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2020 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -36,6 +36,7 @@ using std::ios;
 #include "symmetryPlaneFvPatch.H"
 #include "symmetryFvPatch.H"
 #include "cellModeller.H"
+#include "OSspecific.H"
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
diff --git a/applications/utilities/parallelProcessing/redistributePar/loadOrCreateMesh.C b/applications/utilities/parallelProcessing/redistributePar/loadOrCreateMesh.C
index 19b444737e..428a9be631 100644
--- a/applications/utilities/parallelProcessing/redistributePar/loadOrCreateMesh.C
+++ b/applications/utilities/parallelProcessing/redistributePar/loadOrCreateMesh.C
@@ -26,8 +26,8 @@ License
 #include "loadOrCreateMesh.H"
 #include "processorPolyPatch.H"
 #include "processorCyclicPolyPatch.H"
-#include "Time.H"
 #include "IOPtrList.H"
+#include "OSspecific.H"
 
 // * * * * * * * * * * * * * * * Global Functions  * * * * * * * * * * * * * //
 
diff --git a/applications/utilities/postProcessing/dataConversion/foamToVTK/foamToVTK/writeVTK/writeVTK.C b/applications/utilities/postProcessing/dataConversion/foamToVTK/foamToVTK/writeVTK/writeVTK.C
index 6cf11bb478..8beacf1d7c 100644
--- a/applications/utilities/postProcessing/dataConversion/foamToVTK/foamToVTK/writeVTK/writeVTK.C
+++ b/applications/utilities/postProcessing/dataConversion/foamToVTK/foamToVTK/writeVTK/writeVTK.C
@@ -24,10 +24,10 @@ License
 \*---------------------------------------------------------------------------*/
 
 #include "writeVTK.H"
-#include "dictionary.H"
 #include "Time.H"
 #include "vtkMesh.H"
 #include "internalWriter.H"
+#include "OSspecific.H"
 #include "addToRunTimeSelectionTable.H"
 
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
diff --git a/src/OpenFOAM/db/IOobject/IOobject.C b/src/OpenFOAM/db/IOobject/IOobject.C
index de6e28144d..f2848a52ee 100644
--- a/src/OpenFOAM/db/IOobject/IOobject.C
+++ b/src/OpenFOAM/db/IOobject/IOobject.C
@@ -27,6 +27,7 @@ License
 #include "Time.H"
 #include "IFstream.H"
 #include "registerNamedEnum.H"
+#include "OSspecific.H"
 
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
 
diff --git a/src/OpenFOAM/db/Time/TimeIO.C b/src/OpenFOAM/db/Time/TimeIO.C
index 44c0af69ad..4546fd1ab6 100644
--- a/src/OpenFOAM/db/Time/TimeIO.C
+++ b/src/OpenFOAM/db/Time/TimeIO.C
@@ -29,6 +29,7 @@ License
 #include "dimensionedConstants.H"
 #include "IOdictionary.H"
 #include "fileOperation.H"
+#include "OSspecific.H"
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
diff --git a/src/OpenFOAM/db/dictionary/functionEntries/codeStream/codeStream.C b/src/OpenFOAM/db/dictionary/functionEntries/codeStream/codeStream.C
index 8942010689..8cb4fbfe43 100644
--- a/src/OpenFOAM/db/dictionary/functionEntries/codeStream/codeStream.C
+++ b/src/OpenFOAM/db/dictionary/functionEntries/codeStream/codeStream.C
@@ -27,6 +27,7 @@ License
 #include "dynamicCode.H"
 #include "dynamicCodeContext.H"
 #include "Time.H"
+#include "OSspecific.H"
 #include "addToMemberFunctionSelectionTable.H"
 
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
diff --git a/src/OpenFOAM/db/functionObjects/logFiles/logFiles.C b/src/OpenFOAM/db/functionObjects/logFiles/logFiles.C
index e21d2ea7d6..3cd0232d5c 100644
--- a/src/OpenFOAM/db/functionObjects/logFiles/logFiles.C
+++ b/src/OpenFOAM/db/functionObjects/logFiles/logFiles.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2012-2018 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2012-2020 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -26,6 +26,7 @@ License
 #include "logFiles.H"
 #include "Time.H"
 #include "IFstream.H"
+#include "OSspecific.H"
 
 // * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
 
diff --git a/src/OpenFOAM/db/regIOobject/regIOobject.H b/src/OpenFOAM/db/regIOobject/regIOobject.H
index 7035f6ba95..c3a4131288 100644
--- a/src/OpenFOAM/db/regIOobject/regIOobject.H
+++ b/src/OpenFOAM/db/regIOobject/regIOobject.H
@@ -39,9 +39,6 @@ SourceFiles
 #define regIOobject_H
 
 #include "IOobject.H"
-#include "typeInfo.H"
-#include "OSspecific.H"
-#include "NamedEnum.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
diff --git a/src/conversion/meshWriter/starcd/STARCDMeshWriter.C b/src/conversion/meshWriter/starcd/STARCDMeshWriter.C
index 067d1d8ac2..16a62e2200 100644
--- a/src/conversion/meshWriter/starcd/STARCDMeshWriter.C
+++ b/src/conversion/meshWriter/starcd/STARCDMeshWriter.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2018 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2020 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -24,10 +24,9 @@ License
 \*---------------------------------------------------------------------------*/
 
 #include "STARCDMeshWriter.H"
-
 #include "Time.H"
-#include "SortableList.H"
 #include "OFstream.H"
+#include "OSspecific.H"
 
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
 
diff --git a/src/finiteVolume/fields/fvPatchFields/derived/externalCoupledMixed/externalCoupledMixedFvPatchField.C b/src/finiteVolume/fields/fvPatchFields/derived/externalCoupledMixed/externalCoupledMixedFvPatchField.C
index 421feb3433..104d54ca84 100644
--- a/src/finiteVolume/fields/fvPatchFields/derived/externalCoupledMixed/externalCoupledMixedFvPatchField.C
+++ b/src/finiteVolume/fields/fvPatchFields/derived/externalCoupledMixed/externalCoupledMixedFvPatchField.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2013-2019 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2013-2020 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -28,6 +28,7 @@ License
 #include "volFields.H"
 #include "IFstream.H"
 #include "globalIndex.H"
+#include "OSspecific.H"
 
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
 
diff --git a/src/finiteVolume/fields/fvPatchFields/derived/timeVaryingMappedFixedValue/timeVaryingMappedFvPatchField/timeVaryingMappedFvPatchField.C b/src/finiteVolume/fields/fvPatchFields/derived/timeVaryingMappedFixedValue/timeVaryingMappedFvPatchField/timeVaryingMappedFvPatchField.C
index e2cd59724d..8d3f7ef0fc 100644
--- a/src/finiteVolume/fields/fvPatchFields/derived/timeVaryingMappedFixedValue/timeVaryingMappedFvPatchField/timeVaryingMappedFvPatchField.C
+++ b/src/finiteVolume/fields/fvPatchFields/derived/timeVaryingMappedFixedValue/timeVaryingMappedFvPatchField/timeVaryingMappedFvPatchField.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2019 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2020 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -27,6 +27,7 @@ License
 #include "Time.H"
 #include "AverageField.H"
 #include "IFstream.H"
+#include "OSspecific.H"
 
 // * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
diff --git a/src/functionObjects/utilities/systemCall/systemCall.C b/src/functionObjects/utilities/systemCall/systemCall.C
index 1fda5d7754..49c4d7ed0f 100644
--- a/src/functionObjects/utilities/systemCall/systemCall.C
+++ b/src/functionObjects/utilities/systemCall/systemCall.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2018 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2020 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -26,6 +26,7 @@ License
 #include "systemCall.H"
 #include "Time.H"
 #include "dynamicCode.H"
+#include "OSspecific.H"
 #include "addToRunTimeSelectionTable.H"
 
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
diff --git a/src/functionObjects/utilities/timeActivatedFileUpdate/timeActivatedFileUpdate.C b/src/functionObjects/utilities/timeActivatedFileUpdate/timeActivatedFileUpdate.C
index 2f379f7c53..c8e384793d 100644
--- a/src/functionObjects/utilities/timeActivatedFileUpdate/timeActivatedFileUpdate.C
+++ b/src/functionObjects/utilities/timeActivatedFileUpdate/timeActivatedFileUpdate.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2018 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2020 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -25,7 +25,7 @@ License
 
 #include "timeActivatedFileUpdate.H"
 #include "Time.H"
-#include "polyMesh.H"
+#include "OSspecific.H"
 #include "addToRunTimeSelectionTable.H"
 
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
diff --git a/src/mesh/snappyHexMesh/meshRefinement/meshRefinementBaffles.C b/src/mesh/snappyHexMesh/meshRefinement/meshRefinementBaffles.C
index c6704db39a..fc462730fc 100644
--- a/src/mesh/snappyHexMesh/meshRefinement/meshRefinementBaffles.C
+++ b/src/mesh/snappyHexMesh/meshRefinement/meshRefinementBaffles.C
@@ -24,23 +24,16 @@ License
 \*---------------------------------------------------------------------------*/
 
 #include "meshRefinement.H"
-#include "fvMesh.H"
-#include "syncTools.H"
-#include "Time.H"
 #include "refinementSurfaces.H"
-#include "pointSet.H"
 #include "faceSet.H"
-#include "indirectPrimitivePatch.H"
 #include "polyTopoChange.H"
 #include "meshTools.H"
 #include "polyModifyFace.H"
 #include "polyModifyCell.H"
 #include "polyAddFace.H"
 #include "polyRemoveFace.H"
-#include "polyAddPoint.H"
 #include "localPointRegion.H"
 #include "duplicatePoints.H"
-#include "OFstream.H"
 #include "regionSplit.H"
 #include "removeCells.H"
 #include "unitConversion.H"
@@ -48,6 +41,7 @@ License
 #include "patchFaceOrientation.H"
 #include "PatchEdgeFaceWave.H"
 #include "patchEdgeFaceRegion.H"
+#include "OSspecific.H"
 
 // * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
diff --git a/src/meshTools/sets/faceSources/cellToFace/cellToFace.C b/src/meshTools/sets/faceSources/cellToFace/cellToFace.C
index 4cf0b235ff..f437934b50 100644
--- a/src/meshTools/sets/faceSources/cellToFace/cellToFace.C
+++ b/src/meshTools/sets/faceSources/cellToFace/cellToFace.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2018 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2020 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -28,6 +28,7 @@ License
 #include "cellSet.H"
 #include "Time.H"
 #include "syncTools.H"
+#include "OSspecific.H"
 #include "addToRunTimeSelectionTable.H"
 
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
diff --git a/src/sampling/graphField/makeGraph.C b/src/sampling/graphField/makeGraph.C
index 75853bd2c6..8532dd09ed 100644
--- a/src/sampling/graphField/makeGraph.C
+++ b/src/sampling/graphField/makeGraph.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2019 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2020 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -33,9 +33,9 @@ Description
 
 #include "makeGraph.H"
 #include "volFields.H"
-#include "fvMesh.H"
 #include "graph.H"
 #include "writeFile.H"
+#include "OSspecific.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
diff --git a/src/sampling/graphField/writeCellGraph.C b/src/sampling/graphField/writeCellGraph.C
index bdb9c9dd44..fed96e8b63 100644
--- a/src/sampling/graphField/writeCellGraph.C
+++ b/src/sampling/graphField/writeCellGraph.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2019 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2019-2020 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -25,9 +25,9 @@ License
 
 #include "writeCellGraph.H"
 #include "volFields.H"
-#include "fvMesh.H"
 #include "graph.H"
 #include "writeFile.H"
+#include "OSspecific.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
diff --git a/src/sampling/probes/probes.C b/src/sampling/probes/probes.C
index f69e4faae2..df668ad347 100644
--- a/src/sampling/probes/probes.C
+++ b/src/sampling/probes/probes.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2019 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2020 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -25,10 +25,8 @@ License
 
 #include "probes.H"
 #include "volFields.H"
-#include "dictionary.H"
-#include "Time.H"
-#include "IOmanip.H"
 #include "mapPolyMesh.H"
+#include "OSspecific.H"
 #include "addToRunTimeSelectionTable.H"
 
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
diff --git a/src/sampling/sampledSurface/sampledSurfaces/sampledSurfaces.C b/src/sampling/sampledSurface/sampledSurfaces/sampledSurfaces.C
index e68e44bf0b..bd8e2b80e0 100644
--- a/src/sampling/sampledSurface/sampledSurfaces/sampledSurfaces.C
+++ b/src/sampling/sampledSurface/sampledSurfaces/sampledSurfaces.C
@@ -26,6 +26,7 @@ License
 #include "sampledSurfaces.H"
 #include "PatchTools.H"
 #include "mapPolyMesh.H"
+#include "OSspecific.H"
 #include "addToRunTimeSelectionTable.H"
 
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
diff --git a/src/surfMesh/MeshedSurfaceProxy/MeshedSurfaceProxy.C b/src/surfMesh/MeshedSurfaceProxy/MeshedSurfaceProxy.C
index a9a75186d2..d587dae27b 100644
--- a/src/surfMesh/MeshedSurfaceProxy/MeshedSurfaceProxy.C
+++ b/src/surfMesh/MeshedSurfaceProxy/MeshedSurfaceProxy.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2018 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2020 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -29,6 +29,7 @@ License
 #include "surfMesh.H"
 #include "OFstream.H"
 #include "ListOps.H"
+#include "OSspecific.H"
 
 // * * * * * * * * * * * * * Static Member Functions * * * * * * * * * * * * //
 
diff --git a/src/triSurface/triSurface/triSurface.C b/src/triSurface/triSurface/triSurface.C
index 3c46de79ed..d2338675b3 100644
--- a/src/triSurface/triSurface/triSurface.C
+++ b/src/triSurface/triSurface/triSurface.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2019 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2020 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -35,6 +35,7 @@ License
 #include "tensor2D.H"
 #include "symmTensor2D.H"
 #include "transform.H"
+#include "OSspecific.H"
 
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //