diff --git a/src/OpenFOAM/fields/Fields/transformList/transformList.C b/src/OpenFOAM/fields/Fields/transformList/transformList.C
index f4db4cc6f8..7088bcd7e0 100644
--- a/src/OpenFOAM/fields/Fields/transformList/transformList.C
+++ b/src/OpenFOAM/fields/Fields/transformList/transformList.C
@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2011-2015 OpenFOAM Foundation
-     \\/     M anipulation  |
+     \\/     M anipulation  | Copyright (C) 2018 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -34,14 +34,14 @@ Foam::List<T> Foam::transform
     const UList<T>& field
 )
 {
-    List<T> newField(field.size());
+    List<T> result(field.size());
 
     forAll(field, i)
     {
-        newField[i] = transform(rotTensor, field[i]);
+        result[i] = transform(rotTensor, field[i]);
     }
 
-    return newField;
+    return result;
 }
 
 
@@ -60,10 +60,7 @@ void Foam::transformList(const tensorField& rotTensor, UList<T>& field)
 {
     if (rotTensor.size() == 1)
     {
-        forAll(field, i)
-        {
-            field[i] = transform(rotTensor[0], field[i]);
-        }
+        transformList(rotTensor[0], field);
     }
     else if (rotTensor.size() == field.size())
     {
@@ -87,7 +84,8 @@ void Foam::transformList(const tensor& rotTensor, Map<T>& field)
 {
     forAllIters(field, iter)
     {
-        iter() = transform(rotTensor, iter());
+        T& value = iter.object();
+        value = transform(rotTensor, value);
     }
 }
 
@@ -97,10 +95,7 @@ void Foam::transformList(const tensorField& rotTensor, Map<T>& field)
 {
     if (rotTensor.size() == 1)
     {
-        forAllIter(typename Map<T>, field, iter)
-        {
-            iter() = transform(rotTensor[0], iter());
-        }
+        transformList(rotTensor[0], field);
     }
     else
     {
@@ -117,7 +112,8 @@ void Foam::transformList(const tensor& rotTensor, EdgeMap<T>& field)
 {
     forAllIters(field, iter)
     {
-        iter() = transform(rotTensor, iter());
+        T& value = iter.object();
+        value = transform(rotTensor, value);
     }
 }
 
@@ -127,10 +123,7 @@ void Foam::transformList(const tensorField& rotTensor, EdgeMap<T>& field)
 {
     if (rotTensor.size() == 1)
     {
-        forAllIter(typename EdgeMap<T>, field, iter)
-        {
-            iter() = transform(rotTensor[0], iter());
-        }
+        transformList(rotTensor[0], field);
     }
     else
     {
diff --git a/src/OpenFOAM/fields/Fields/transformList/transformList.H b/src/OpenFOAM/fields/Fields/transformList/transformList.H
index 8b485bec41..9f827d0928 100644
--- a/src/OpenFOAM/fields/Fields/transformList/transformList.H
+++ b/src/OpenFOAM/fields/Fields/transformList/transformList.H
@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2011-2016 OpenFOAM Foundation
-     \\/     M anipulation  |
+     \\/     M anipulation  | Copyright (C) 2018 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -25,7 +25,7 @@ InClass
     Foam
 
 Description
-    Spatial transformation functions for primitive fields.
+    Spatial transformation functions for list of values and primitive fields.
 
 SourceFiles
     transformList.C
@@ -41,7 +41,6 @@ SourceFiles
 #include "edgeHashes.H"
 #include "tensorField.H"
 
-
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 namespace Foam
@@ -49,93 +48,63 @@ namespace Foam
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
-//- Extend transform to work on list.
+//- Apply transform to a list of elements, returning a copy.
 template<class T>
-List<T> transform
-(
-    const tensor& rotTensor,
-    const UList<T>& field
-);
+List<T> transform(const tensor& rotTensor, const UList<T>& field);
 
-//- Apply transformation to list. Either single transformation tensor
-//  or one tensor per element.
+//- Inplace transform a list of elements.
 template<class T>
-void transformList(const tensor&, UList<T>&);
+void transformList(const tensor& rotTensor, UList<T>& field);
+
+//- Inplace transform a list of elements using one tensor per element.
 template<class T>
-void transformList(const tensorField&, UList<T>&);
+void transformList(const tensorField& rotTensor, UList<T>& field);
 
+//- Inplace transform a Map of elements.
 template<class T>
-void transformList(const tensor&, Map<T>&);
+void transformList(const tensor& rotTensor, Map<T>& field);
+
+//- Inplace transform a Map of elements using one tensor per element.
+//  Using multiple tensors is ill-defined (Fatal).
 template<class T>
-void transformList(const tensorField&, Map<T>&);
+void transformList(const tensorField& rotTensor, Map<T>& field);
 
+//- Inplace transform a Map of elements.
+//  Using multiple tensors is ill-defined (Fatal).
 template<class T>
-void transformList(const tensor&, EdgeMap<T>&);
+void transformList(const tensor& rotTensor, EdgeMap<T>& field);
+
+//- Inplace transform a Map of elements using one tensor per element.
+//  Using multiple tensors is ill-defined (Fatal).
 template<class T>
-void transformList(const tensorField&, EdgeMap<T>&);
+void transformList(const tensorField& rotTensor, EdgeMap<T>& field);
 
 
-// Specialisations for bool
-template<>
-inline void transformList(const tensor&, UList<bool>&)
-{}
-template<>
-inline void transformList(const tensorField&, UList<bool>&)
-{}
-template<>
-inline void transformList(const tensor&, Map<bool>&)
-{}
-template<>
-inline void transformList(const tensorField&, Map<bool>&)
-{}
-template<>
-inline void transformList(const tensor&, EdgeMap<bool>&)
-{}
-template<>
-inline void transformList(const tensorField&, EdgeMap<bool>&)
-{}
+// Specialisations for bool (no-op)
+template<> inline void transformList(const tensor&, UList<bool>&) {}
+template<> inline void transformList(const tensorField&, UList<bool>&) {}
+template<> inline void transformList(const tensor&, Map<bool>&) {}
+template<> inline void transformList(const tensorField&, Map<bool>&) {}
+template<> inline void transformList(const tensor&, EdgeMap<bool>&) {}
+template<> inline void transformList(const tensorField&, EdgeMap<bool>&) {}
 
 
-// Specialisations for label
-template<>
-inline void transformList(const tensor&, labelUList&)
-{}
-template<>
-inline void transformList(const tensorField&, labelUList&)
-{}
-template<>
-inline void transformList(const tensor&, Map<label>&)
-{}
-template<>
-inline void transformList(const tensorField&, Map<label>&)
-{}
-template<>
-inline void transformList(const tensor&, EdgeMap<label>&)
-{}
-template<>
-inline void transformList(const tensorField&, EdgeMap<label>&)
-{}
+// Specialisations for label (no-op)
+template<> inline void transformList(const tensor&, labelUList&) {}
+template<> inline void transformList(const tensorField&, labelUList&) {}
+template<> inline void transformList(const tensor&, Map<label>&) {}
+template<> inline void transformList(const tensorField&, Map<label>&) {}
+template<> inline void transformList(const tensor&, EdgeMap<label>&) {}
+template<> inline void transformList(const tensorField&, EdgeMap<label>&) {}
 
 
-// Specialisations for scalar
-template<>
-inline void transformList(const tensor&, UList<scalar>&)
-{}
-template<>
-inline void transformList(const tensorField&, UList<scalar>&)
-{}
-template<>
-inline void transformList(const tensor&, Map<scalar>&)
-{}
-template<>
-inline void transformList(const tensorField&, Map<scalar>&)
-{}
-template<>
-inline void transformList(const tensor&, EdgeMap<scalar>&)
-{}
-template<>
-inline void transformList(const tensorField&, EdgeMap<scalar>&)
-{}
+// Specialisations for scalar (no-op)
+template<> inline void transformList(const tensor&, UList<scalar>&) {}
+template<> inline void transformList(const tensorField&, UList<scalar>&) {}
+template<> inline void transformList(const tensor&, Map<scalar>&) {}
+template<> inline void transformList(const tensorField&, Map<scalar>&) {}
+template<> inline void transformList(const tensor&, EdgeMap<scalar>&) {}
+template<> inline void transformList(const tensorField&, EdgeMap<scalar>&) {}
 
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
diff --git a/src/OpenFOAM/primitives/transform/transform.H b/src/OpenFOAM/primitives/transform/transform.H
index 9fd1318acc..8f9c09c290 100644
--- a/src/OpenFOAM/primitives/transform/transform.H
+++ b/src/OpenFOAM/primitives/transform/transform.H
@@ -142,31 +142,38 @@ inline tensor Ra(const vector& a, const scalar omega)
 }
 
 
-inline label transform(const tensor&, const bool i)
+//- No-op rotational transform of a bool
+inline bool transform(const tensor&, const bool b)
 {
-    return i;
+    return b;
 }
 
 
+//- No-op rotational transform of a label
 inline label transform(const tensor&, const label i)
 {
     return i;
 }
 
 
+//- No-op rotational transform of a label
 inline scalar transform(const tensor&, const scalar s)
 {
     return s;
 }
 
 
+//- Use rotational tensor to transform a vector.
+//  Same as (rot & v)
 template<class Cmpt>
 inline Vector<Cmpt> transform(const tensor& tt, const Vector<Cmpt>& v)
 {
-    return tt & v;
+    return (tt & v);
 }
 
 
+//- Use rotational tensor to transform a tensor.
+//  Same as (rot & input & rot.T())
 template<class Cmpt>
 inline Tensor<Cmpt> transform(const tensor& tt, const Tensor<Cmpt>& t)
 {
@@ -211,6 +218,7 @@ inline Tensor<Cmpt> transform(const tensor& tt, const Tensor<Cmpt>& t)
 }
 
 
+//- Use rotational tensor to transform a spherical tensor (no-op).
 template<class Cmpt>
 inline SphericalTensor<Cmpt> transform
 (
@@ -222,6 +230,8 @@ inline SphericalTensor<Cmpt> transform
 }
 
 
+//- Use rotational tensor to transform a symmetrical tensor.
+//  Same as (rot & input & rot.T())
 template<class Cmpt>
 inline SymmTensor<Cmpt> transform(const tensor& tt, const SymmTensor<Cmpt>& st)
 {
@@ -292,16 +302,16 @@ inline scalar pseudoAngle
     const vector& vec
 )
 {
-    scalar cos = vec & e0;
-    scalar sin = vec & e1;
+    const scalar cos_angle = vec & e0;
+    const scalar sin_angle = vec & e1;
 
-    if (sin < -SMALL)
+    if (sin_angle < -SMALL)
     {
-        return (3.0 + cos)*constant::mathematical::piByTwo;
+        return (3.0 + cos_angle)*constant::mathematical::piByTwo;
     }
     else
     {
-        return (1.0 - cos)*constant::mathematical::piByTwo;
+        return (1.0 - cos_angle)*constant::mathematical::piByTwo;
     }
 }