diff --git a/src/OpenFOAM/containers/Dictionaries/Dictionary/Dictionary.C b/src/OpenFOAM/containers/Dictionaries/Dictionary/Dictionary.C
index 8709ba6fbc..7cec1b4541 100644
--- a/src/OpenFOAM/containers/Dictionaries/Dictionary/Dictionary.C
+++ b/src/OpenFOAM/containers/Dictionaries/Dictionary/Dictionary.C
@@ -1,64 +1 @@
-/*---------------------------------------------------------------------------*\
-  =========                 |
-  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
-   \\    /   O peration     |
-    \\  /    A nd           | www.openfoam.com
-     \\/     M anipulation  |
--------------------------------------------------------------------------------
-    Copyright (C) 2011-2013 OpenFOAM Foundation
-    Copyright (C) 2019 OpenCFD Ltd.
--------------------------------------------------------------------------------
-License
-    This file is part of OpenFOAM.
-
-    OpenFOAM is free software: you can redistribute it and/or modify it
-    under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
-    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
-    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
-    for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
-
-\*---------------------------------------------------------------------------*/
-
-#include "Dictionary.H"
-
-// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
-
-template<class T>
-Foam::Dictionary<T>::Dictionary(const label size)
-:
-    DictionaryBase<IDLList<T>, T>(size)
-{}
-
-
-template<class T>
-Foam::Dictionary<T>::Dictionary(const Dictionary& dict)
-:
-    DictionaryBase<IDLList<T>, T>(dict)
-{}
-
-
-// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
-
-template<class T>
-bool Foam::Dictionary<T>::erase(const word& keyword)
-{
-    T* ptr = this->remove(keyword);
-
-    if (ptr)
-    {
-        delete ptr;
-        return true;
-    }
-
-    return false;
-}
-
-
-// ************************************************************************* //
+#warning File removed - left for old dependency check only
diff --git a/src/OpenFOAM/containers/Dictionaries/Dictionary/Dictionary.H b/src/OpenFOAM/containers/Dictionaries/Dictionary/Dictionary.H
index db5ace7e53..96f4c359d7 100644
--- a/src/OpenFOAM/containers/Dictionaries/Dictionary/Dictionary.H
+++ b/src/OpenFOAM/containers/Dictionaries/Dictionary/Dictionary.H
@@ -34,13 +34,10 @@ Description
     It is derived from DictionaryBase instantiated on a memory managed form
     of intrusive doubly-linked list of \<T\>.
 
-SourceFiles
-    Dictionary.C
-
 \*---------------------------------------------------------------------------*/
 
-#ifndef Dictionary_H
-#define Dictionary_H
+#ifndef Foam_Dictionary_H
+#define Foam_Dictionary_H
 
 #include "DictionaryBase.H"
 #include "IDLList.H"
@@ -61,35 +58,43 @@ class Dictionary
 {
 public:
 
+    //- The template instance used for the dictionary content
+    typedef DictionaryBase<IDLList<T>, T> dict_type;
+
+
     // Constructors
 
-        //- Construct with given or default (128) table capacity
-        explicit Dictionary(const label size = 128);
+        //- Default construct, or with initial table capacity
+        explicit Dictionary(const label initialCapacity = 128)
+        :
+            dict_type(initialCapacity)
+        {}
 
         //- Copy construct
-        Dictionary(const Dictionary& dict);
+        Dictionary(const Dictionary& dict)
+        :
+            dict_type(dict)
+        {}
 
 
     // Member Functions
 
         //- Remove an entry specified by keyword and delete the pointer.
         //  \return true if the keyword was found
-        bool erase(const word& keyword);
+        bool erase(const word& keyword)
+        {
+            T* ptr = this->remove(keyword);
+            delete ptr;
+            return bool(ptr);
+        }
 };
 
-
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 } // End namespace Foam
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
-#ifdef NoRepository
-    #include "Dictionary.C"
-#endif
-
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
 #endif
 
 // ************************************************************************* //
diff --git a/src/OpenFOAM/containers/Dictionaries/DictionaryBase/DictionaryBase.C b/src/OpenFOAM/containers/Dictionaries/DictionaryBase/DictionaryBase.C
index a0483d57aa..6709eeb52d 100644
--- a/src/OpenFOAM/containers/Dictionaries/DictionaryBase/DictionaryBase.C
+++ b/src/OpenFOAM/containers/Dictionaries/DictionaryBase/DictionaryBase.C
@@ -42,13 +42,6 @@ void Foam::DictionaryBase<IDLListType, T>::addEntries()
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
-template<class IDLListType, class T>
-Foam::DictionaryBase<IDLListType, T>::DictionaryBase(const label size)
-:
-    hashedTs_(size)
-{}
-
-
 template<class IDLListType, class T>
 Foam::DictionaryBase<IDLListType, T>::DictionaryBase
 (
@@ -156,34 +149,6 @@ T* Foam::DictionaryBase<IDLListType, T>::lookup(const word& keyword)
 }
 
 
-template<class IDLListType, class T>
-Foam::wordList Foam::DictionaryBase<IDLListType, T>::toc() const
-{
-    // Cannot rely on the items themselves having a keyword() method
-    // so simply return the toc() from the hashed entries
-    // Make it sorted, since anything else would have no meaning.
-    return hashedTs_.sortedToc();
-}
-
-
-template<class IDLListType, class T>
-Foam::wordList Foam::DictionaryBase<IDLListType, T>::sortedToc() const
-{
-    return hashedTs_.sortedToc();
-}
-
-
-template<class IDLListType, class T>
-template<class Compare>
-Foam::wordList Foam::DictionaryBase<IDLListType, T>::sortedToc
-(
-    const Compare& comp
-) const
-{
-    return hashedTs_.sortedToc(comp);
-}
-
-
 template<class IDLListType, class T>
 void Foam::DictionaryBase<IDLListType, T>::push_front
 (
@@ -191,9 +156,9 @@ void Foam::DictionaryBase<IDLListType, T>::push_front
     T* ptr
 )
 {
+    IDLListType::push_front(ptr);
     // NOTE: we should probably check that HashTable::insert actually worked
     hashedTs_.insert(keyword, ptr);
-    IDLListType::push_front(ptr);
 }
 
 
@@ -213,16 +178,15 @@ void Foam::DictionaryBase<IDLListType, T>::push_back
 template<class IDLListType, class T>
 T* Foam::DictionaryBase<IDLListType, T>::remove(const word& keyword)
 {
+    T* ptr = nullptr;
     auto iter = hashedTs_.find(keyword);
 
     if (iter.good())
     {
-        T* ptr = IDLListType::remove(iter.val());
+        ptr = IDLListType::remove(iter.val());
         hashedTs_.erase(iter);
-        return ptr;
     }
-
-    return nullptr;
+    return ptr;
 }
 
 
@@ -269,8 +233,4 @@ void Foam::DictionaryBase<IDLListType, T>::operator=
 }
 
 
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
-#include "DictionaryBaseIO.C"
-
 // ************************************************************************* //
diff --git a/src/OpenFOAM/containers/Dictionaries/DictionaryBase/DictionaryBase.H b/src/OpenFOAM/containers/Dictionaries/DictionaryBase/DictionaryBase.H
index 6d14d85d04..9073637892 100644
--- a/src/OpenFOAM/containers/Dictionaries/DictionaryBase/DictionaryBase.H
+++ b/src/OpenFOAM/containers/Dictionaries/DictionaryBase/DictionaryBase.H
@@ -87,7 +87,13 @@ protected:
 
     // Protected Member Functions
 
-        // Add the IDLListType entries into the HashTable
+        //- Add an entry to the HashTable
+        bool addHashEntry(const word& key, T* ptr)
+        {
+            return hashedTs_.insert(key, ptr);
+        }
+
+        //- Add the IDLListType entries into the HashTable
         void addEntries();
 
 
@@ -96,7 +102,10 @@ public:
     // Constructors
 
         //- Construct with given or default (128) table capacity
-        explicit DictionaryBase(const label size = 128);
+        explicit DictionaryBase(const label initialCapacity = 128)
+        :
+            hashedTs_(initialCapacity)
+        {}
 
         //- Copy construct
         DictionaryBase(const DictionaryBase& dict);
@@ -128,15 +137,24 @@ public:
             //- Find and return entry, FatalError on failure.
             T* lookup(const word& keyword);
 
-            //- Return the table of contents (as a sorted list)
-            wordList toc() const;
+            //- The table of contents (as a sorted list)
+            wordList toc() const
+            {
+                return hashedTs_.sortedToc();
+            }
 
-            //- Return the table of contents as a sorted list
-            wordList sortedToc() const;
+            //- The table of contents as a sorted list
+            wordList sortedToc() const
+            {
+                return hashedTs_.sortedToc();
+            }
 
-            //- Return table of contents sorted using the specified comparator
+            //- The table of contents sorted using the specified comparator
             template<class Compare>
-            wordList sortedToc(const Compare& comp) const;
+            wordList sortedToc(const Compare& comp) const
+            {
+                return hashedTs_.sortedToc(comp);
+            }
 
 
         // Editing
@@ -194,39 +212,24 @@ public:
         //- Deprecated(2020-03) use cfind()
         //  \deprecated(2020-03) - use cfind() method
         FOAM_DEPRECATED_FOR(2020-03, "cfind() method")
-        const T* lookupPtr(const word& keyword) const
-        {
-            return this->cfind(keyword);
-        }
+        const T* lookupPtr(const word& k) const { return this->cfind(k); }
 
         //- Deprecated(2020-03) use find()
         //  \deprecated(2020-03) - use find() method
         FOAM_DEPRECATED_FOR(2020-03, "find() method")
-        T* lookupPtr(const word& keyword)
-        {
-            return this->find(keyword);
-        }
+        T* lookupPtr(const word& k) { return this->find(k); }
 
         //- Add to front of dictionary
         //FOAM_DEPRECATED_FOR(2022-10, "push_front()")
-        void insert(const word& keyword, T* ptr)
-        {
-            this->push_front(keyword, ptr);
-        }
+        void insert(const word& k, T* ptr) { this->push_front(k, ptr); }
 
         //- Add to front of dictionary
         //FOAM_DEPRECATED_FOR(2022-10, "push_front()")
-        void prepend(const word& keyword, T* ptr)
-        {
-            this->push_front(keyword, ptr);
-        }
+        void prepend(const word& k, T* ptr) { this->push_front(k, ptr); }
 
         //- Add to back of dictionary
         //FOAM_DEPRECATED_FOR(2022-10, "push_back()")
-        void append(const word& keyword, T* ptr)
-        {
-            this->push_back(keyword, ptr);
-        }
+        void append(const word& k, T* ptr) { this->push_back(k, ptr); }
 };
 
 
@@ -238,6 +241,7 @@ public:
 
 #ifdef NoRepository
     #include "DictionaryBase.C"
+    #include "DictionaryBaseIO.C"
 #endif
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
diff --git a/src/OpenFOAM/containers/Dictionaries/DictionaryBase/DictionaryBaseIO.C b/src/OpenFOAM/containers/Dictionaries/DictionaryBase/DictionaryBaseIO.C
index 77a3c5c4ea..1a0dc97367 100644
--- a/src/OpenFOAM/containers/Dictionaries/DictionaryBase/DictionaryBaseIO.C
+++ b/src/OpenFOAM/containers/Dictionaries/DictionaryBase/DictionaryBaseIO.C
@@ -35,9 +35,10 @@ template<class IDLListType, class T>
 Foam::Ostream& Foam::operator<<
 (
     Ostream& os,
-    const DictionaryBase<IDLListType, T>& dict)
+    const DictionaryBase<IDLListType, T>& dict
+)
 {
-    for (auto iter = dict.begin(); iter != dict.end(); ++iter)
+    for (auto iter = dict.cbegin(); iter != dict.cend(); ++iter)
     {
         os << *iter;
 
diff --git a/src/OpenFOAM/containers/Dictionaries/PtrDictionary/PtrDictionary.H b/src/OpenFOAM/containers/Dictionaries/PtrDictionary/PtrDictionary.H
index 4581c1c231..116fdef855 100644
--- a/src/OpenFOAM/containers/Dictionaries/PtrDictionary/PtrDictionary.H
+++ b/src/OpenFOAM/containers/Dictionaries/PtrDictionary/PtrDictionary.H
@@ -56,31 +56,35 @@ class PtrDictionary
 {
 public:
 
+    //- The template instance used for the dictionary content
+    typedef DictionaryBase<DLPtrList<T>, T> dict_type;
+
+
     // Constructors
 
-        //- Construct given initial table size
-        explicit PtrDictionary(const label size = 128)
+        //- Default construct, or with initial table capacity
+        explicit PtrDictionary(const label initialCapacity = 128)
         :
-            DictionaryBase<DLPtrList<T>, T>(size)
+            dict_type(initialCapacity)
         {}
 
         //- Copy construct
         PtrDictionary(const PtrDictionary& dict)
         :
-            DictionaryBase<DLPtrList<T>, T>(dict)
+            dict_type(dict)
         {}
 
         //- Construct from Istream using given Istream constructor class
         template<class INew>
         PtrDictionary(Istream& is, const INew& inew)
         :
-            DictionaryBase<DLPtrList<T>, T>(is, inew)
+            dict_type(is, inew)
         {}
 
         //- Construct from Istream
         explicit PtrDictionary(Istream& is)
         :
-            DictionaryBase<DLPtrList<T>, T>(is)
+            dict_type(is)
         {}
 
 
@@ -89,13 +93,13 @@ public:
         //- Find and return entry
         const T& operator[](const word& key) const
         {
-            return *DictionaryBase<DLPtrList<T>, T>::operator[](key);
+            return *(dict_type::lookup(key));
         }
 
         //- Find and return entry
         T& operator[](const word& key)
         {
-            return *DictionaryBase<DLPtrList<T>, T>::operator[](key);
+            return *(dict_type::lookup(key));
         }
 };
 
diff --git a/src/OpenFOAM/containers/Dictionaries/PtrListDictionary/PtrListDictionary.C b/src/OpenFOAM/containers/Dictionaries/PtrListDictionary/PtrListDictionary.C
index 4cad8cb575..e42946da7d 100644
--- a/src/OpenFOAM/containers/Dictionaries/PtrListDictionary/PtrListDictionary.C
+++ b/src/OpenFOAM/containers/Dictionaries/PtrListDictionary/PtrListDictionary.C
@@ -32,7 +32,7 @@ License
 template<class T>
 Foam::PtrListDictionary<T>::PtrListDictionary(const label size)
 :
-    DictionaryBase<PtrList<T>, T>(2*size)
+    dict_type(2*size)
 {
     PtrList<T>::resize(size);
 }
@@ -41,7 +41,7 @@ Foam::PtrListDictionary<T>::PtrListDictionary(const label size)
 template<class T>
 Foam::PtrListDictionary<T>::PtrListDictionary(const PtrListDictionary& dict)
 :
-    DictionaryBase<PtrList<T>, T>(dict)
+    dict_type(dict)
 {}
 
 
@@ -49,14 +49,14 @@ template<class T>
 template<class INew>
 Foam::PtrListDictionary<T>::PtrListDictionary(Istream& is, const INew& iNew)
 :
-    DictionaryBase<PtrList<T>, T>(is, iNew)
+    dict_type(is, iNew)
 {}
 
 
 template<class T>
 Foam::PtrListDictionary<T>::PtrListDictionary(Istream& is)
 :
-    DictionaryBase<PtrList<T>, T>(is)
+    dict_type(is)
 {}
 
 
@@ -70,13 +70,16 @@ inline Foam::autoPtr<T> Foam::PtrListDictionary<T>::set
     T* ptr
 )
 {
-    if (!DictionaryBase<PtrList<T>, T>::hashedTs_.insert(key, ptr))
+    autoPtr<T> old(PtrList<T>::set(i, ptr));
+
+    if (!dict_type::addHashEntry(key, ptr))
     {
         FatalErrorInFunction
             << "Cannot insert with key '" << key << "' into hash-table"
             << abort(FatalError);
     }
-    return PtrList<T>::set(i, ptr);
+
+    return old;
 }
 
 
@@ -85,17 +88,10 @@ inline Foam::autoPtr<T> Foam::PtrListDictionary<T>::set
 (
     const label i,
     const word& key,
-    autoPtr<T>& aptr
+    autoPtr<T>& ptr
 )
 {
-    T* ptr = aptr.ptr();
-    if (!DictionaryBase<PtrList<T>, T>::hashedTs_.insert(key, ptr))
-    {
-        FatalErrorInFunction
-            << "Cannot insert with key '" << key << "' into hash-table"
-            << abort(FatalError);
-    }
-    return PtrList<T>::set(i, ptr);
+    return this->set(i, key, ptr.release());
 }
 
 
@@ -104,17 +100,10 @@ inline Foam::autoPtr<T> Foam::PtrListDictionary<T>::set
 (
     const label i,
     const word& key,
-    tmp<T>& t
+    tmp<T>& ptr
 )
 {
-    T* ptr = t.ptr();
-    if (!DictionaryBase<PtrList<T>, T>::hashedTs_.insert(key, ptr))
-    {
-        FatalErrorInFunction
-            << "Cannot insert with key '" << key << "' into hash-table"
-            << abort(FatalError);
-    }
-    return PtrList<T>::set(i, ptr);
+    return this->set(i, key, ptr.ptr());  // release or clone
 }
 
 
diff --git a/src/OpenFOAM/containers/Dictionaries/PtrListDictionary/PtrListDictionary.H b/src/OpenFOAM/containers/Dictionaries/PtrListDictionary/PtrListDictionary.H
index a221dd6a2d..9660e5c0e6 100644
--- a/src/OpenFOAM/containers/Dictionaries/PtrListDictionary/PtrListDictionary.H
+++ b/src/OpenFOAM/containers/Dictionaries/PtrListDictionary/PtrListDictionary.H
@@ -59,6 +59,10 @@ class PtrListDictionary
 {
 public:
 
+    //- The template instance used for the dictionary content
+    typedef DictionaryBase<PtrList<T>, T> dict_type;
+
+
     // Constructors
 
         //- Construct given initial list size
@@ -81,26 +85,26 @@ public:
         autoPtr<T> set(const label i, const word& key, T* ptr);
 
         //- Set element to autoPtr value provided and return old element
-        autoPtr<T> set(const label i, const word& key, autoPtr<T>& aptr);
+        autoPtr<T> set(const label i, const word& key, autoPtr<T>& ptr);
 
         //- Set element to tmp value provided and return old element
-        autoPtr<T> set(const label i, const word& key, tmp<T>& t);
+        autoPtr<T> set(const label i, const word& key, tmp<T>& ptr);
 
 
-    // Member operators
+    // Member Operators
 
         using PtrList<T>::operator[];
 
         //- Find and return entry
         const T& operator[](const word& key) const
         {
-            return *DictionaryBase<PtrList<T>, T>::operator[](key);
+            return *(dict_type::lookup(key));
         }
 
         //- Find and return entry
         T& operator[](const word& key)
         {
-            return *DictionaryBase<PtrList<T>, T>::operator[](key);
+            return *(dict_type::lookup(key));
         }
 };
 
diff --git a/src/OpenFOAM/containers/Dictionaries/UDictionary/UDictionary.C b/src/OpenFOAM/containers/Dictionaries/UDictionary/UDictionary.C
deleted file mode 100644
index a233e756cc..0000000000
--- a/src/OpenFOAM/containers/Dictionaries/UDictionary/UDictionary.C
+++ /dev/null
@@ -1,46 +0,0 @@
-/*---------------------------------------------------------------------------*\
-  =========                 |
-  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
-   \\    /   O peration     |
-    \\  /    A nd           | www.openfoam.com
-     \\/     M anipulation  |
--------------------------------------------------------------------------------
-    Copyright (C) 2011 OpenFOAM Foundation
--------------------------------------------------------------------------------
-License
-    This file is part of OpenFOAM.
-
-    OpenFOAM is free software: you can redistribute it and/or modify it
-    under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
-    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
-    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
-    for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
-
-\*---------------------------------------------------------------------------*/
-
-#include "UDictionary.H"
-
-// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
-
-template<class T>
-Foam::UDictionary<T>::UDictionary()
-{}
-
-
-template<class T>
-Foam::UDictionary<T>::UDictionary(const UDictionary& dict)
-:
-    DictionaryBase<UIDLList<T>, T>(dict)
-{}
-
-
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
-// ************************************************************************* //
diff --git a/src/OpenFOAM/containers/Dictionaries/UDictionary/UDictionary.H b/src/OpenFOAM/containers/Dictionaries/UDictionary/UDictionary.H
index 0f8fa93d41..dac3fcb69c 100644
--- a/src/OpenFOAM/containers/Dictionaries/UDictionary/UDictionary.H
+++ b/src/OpenFOAM/containers/Dictionaries/UDictionary/UDictionary.H
@@ -33,13 +33,10 @@ Description
     It is derived from DictionaryBase instantiated on a non-memory managed
     form of intrusive doubly-linked list of \<T\>.
 
-SourceFiles
-    UDictionary.C
-
 \*---------------------------------------------------------------------------*/
 
-#ifndef UDictionary_H
-#define UDictionary_H
+#ifndef Foam_UDictionary_H
+#define Foam_UDictionary_H
 
 #include "DictionaryBase.H"
 #include "UIDLList.H"
@@ -58,16 +55,25 @@ class UDictionary
 :
     public DictionaryBase<UIDLList<T>, T>
 {
-
 public:
 
+    //- The template instance used for the dictionary content
+    typedef DictionaryBase<UIDLList<T>, T> dict_type;
+
+
     // Constructors
 
-        //- Null constructor
-        UDictionary();
+        //- Default construct, or with initial table capacity
+        explicit UDictionary(const label initialCapacity = 128)
+        :
+            dict_type(initialCapacity)
+        {}
 
         //- Copy construct
-        UDictionary(const UDictionary&);
+        UDictionary(const UDictionary& dict)
+        :
+            dict_type(dict)
+        {}
 };
 
 
@@ -77,12 +83,6 @@ public:
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
-#ifdef NoRepository
-    #include "UDictionary.C"
-#endif
-
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
 #endif
 
 // ************************************************************************* //
diff --git a/src/OpenFOAM/containers/Dictionaries/UPtrDictionary/UPtrDictionary.H b/src/OpenFOAM/containers/Dictionaries/UPtrDictionary/UPtrDictionary.H
index 1ff0b8bde4..fa5729a2c3 100644
--- a/src/OpenFOAM/containers/Dictionaries/UPtrDictionary/UPtrDictionary.H
+++ b/src/OpenFOAM/containers/Dictionaries/UPtrDictionary/UPtrDictionary.H
@@ -57,18 +57,22 @@ class UPtrDictionary
 {
 public:
 
+    //- The template instance used for the dictionary content
+    typedef DictionaryBase<DLList<T*>, T> dict_type;
+
+
     // Constructors
 
-        //- Construct given initial table size
-        explicit UPtrDictionary(const label size = 128)
+        //- Default construct, or with initial table capacity
+        explicit UPtrDictionary(const label initialCapacity = 128)
         :
-            DictionaryBase<DLList<T*>, T>(size)
+            dict_type(initialCapacity)
         {}
 
         //- Copy construct
         UPtrDictionary(const UPtrDictionary& dict)
         :
-            DictionaryBase<DLList<T*>, T>(dict)
+            dict_type(dict)
         {}
 };
 
diff --git a/src/OpenFOAM/containers/HashTables/HashPtrTable/HashPtrTable.H b/src/OpenFOAM/containers/HashTables/HashPtrTable/HashPtrTable.H
index 39d2fbff68..3d15ee7087 100644
--- a/src/OpenFOAM/containers/HashTables/HashPtrTable/HashPtrTable.H
+++ b/src/OpenFOAM/containers/HashTables/HashPtrTable/HashPtrTable.H
@@ -96,14 +96,26 @@ public:
         //- Default construct with default table capacity
         HashPtrTable() = default;
 
+        //- Construct with zero table capacity
+        explicit HashPtrTable(const Foam::zero) noexcept
+        :
+            parent_type(Foam::zero{})
+        {}
+
         //- Construct given initial table capacity
-        inline explicit HashPtrTable(const label size);
+        explicit HashPtrTable(const label initialCapacity)
+        :
+            parent_type(initialCapacity)
+        {}
 
         //- Copy construct, making a copy of each element
         HashPtrTable(const this_type& rhs);
 
         //- Move construct
-        inline HashPtrTable(this_type&& rhs);
+        HashPtrTable(this_type&& rhs) noexcept
+        :
+            parent_type(std::move(rhs))
+        {}
 
         //- Construct from Istream using given Istream constructor class
         template<class INew>
diff --git a/src/OpenFOAM/containers/HashTables/HashPtrTable/HashPtrTableI.H b/src/OpenFOAM/containers/HashTables/HashPtrTable/HashPtrTableI.H
index 2d3f8a4921..8c0a97f4e1 100644
--- a/src/OpenFOAM/containers/HashTables/HashPtrTable/HashPtrTableI.H
+++ b/src/OpenFOAM/containers/HashTables/HashPtrTable/HashPtrTableI.H
@@ -29,25 +29,6 @@ License
 #include "refPtr.H"
 #include "tmp.H"
 
-// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
-
-template<class T, class Key, class Hash>
-inline Foam::HashPtrTable<T, Key, Hash>::HashPtrTable(const label size)
-:
-    parent_type(size)
-{}
-
-
-template<class T, class Key, class Hash>
-inline Foam::HashPtrTable<T, Key, Hash>::HashPtrTable
-(
-    HashPtrTable<T, Key, Hash>&& rhs
-)
-:
-    parent_type(std::move(rhs))
-{}
-
-
 // * * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * //
 
 template<class T, class Key, class Hash>
diff --git a/src/OpenFOAM/containers/HashTables/HashSet/HashSet.C b/src/OpenFOAM/containers/HashTables/HashSet/HashSet.C
index 7457fc6b30..abae7f59a6 100644
--- a/src/OpenFOAM/containers/HashTables/HashSet/HashSet.C
+++ b/src/OpenFOAM/containers/HashTables/HashSet/HashSet.C
@@ -287,8 +287,12 @@ void Foam::HashSet<Key, Hash>::operator=(std::initializer_list<Key> rhs)
 template<class Key, class Hash>
 bool Foam::HashSet<Key, Hash>::operator==(const HashSet<Key, Hash>& rhs) const
 {
-    // Sizes (number of keys) must match
-    if (this->size() != rhs.size())
+    // Trivial checks first
+    if (this == &rhs)
+    {
+        return true;
+    }
+    else if (this->size() != rhs.size())
     {
         return false;
     }
@@ -316,10 +320,13 @@ template<class Key, class Hash>
 Foam::HashSet<Key, Hash>&
 Foam::HashSet<Key, Hash>::operator|=(const HashSet<Key, Hash>& rhs)
 {
-    // Add rhs elements into lhs
-    for (const_iterator iter = rhs.cbegin(); iter != rhs.cend(); ++iter)
+    // Add rhs elements into lhs - avoid no-ops
+    if (this != &rhs)
     {
-        this->insert(iter.key());
+        for (const_iterator iter = rhs.cbegin(); iter != rhs.cend(); ++iter)
+        {
+            this->insert(iter.key());
+        }
     }
 
     return *this;
diff --git a/src/OpenFOAM/containers/HashTables/HashSet/HashSet.H b/src/OpenFOAM/containers/HashTables/HashSet/HashSet.H
index cf659ecbaa..b02b18ace4 100644
--- a/src/OpenFOAM/containers/HashTables/HashSet/HashSet.H
+++ b/src/OpenFOAM/containers/HashTables/HashSet/HashSet.H
@@ -124,10 +124,19 @@ public:
 
     // Constructors
 
-        //- Default construct with default (128) table capacity
-        HashSet()
+        //- Default construct with default (128) initial table capacity
+        HashSet() = default;
+
+        //- Construct empty with zero table capacity
+        explicit HashSet(const Foam::zero) noexcept
         :
-            parent_type()
+            parent_type(Foam::zero{})
+        {}
+
+        //- Construct empty with initial table capacity
+        explicit HashSet(const label initialCapacity)
+        :
+            parent_type(initialCapacity)
         {}
 
         //- Copy construct
@@ -137,18 +146,12 @@ public:
         {}
 
         //- Move construct
-        HashSet(this_type&& rhs)
+        HashSet(this_type&& rhs) noexcept
         :
             parent_type(std::move(rhs))
         {}
 
-        //- Construct given initial table capacity
-        explicit HashSet(const label size)
-        :
-            parent_type(size)
-        {}
-
-        //- Construct from Istream with default table capacity
+        //- Construct from Istream with default initial table capacity
         explicit HashSet(Istream& is)
         :
             parent_type(is)
diff --git a/src/OpenFOAM/containers/HashTables/HashTable/HashTable.C b/src/OpenFOAM/containers/HashTables/HashTable/HashTable.C
index e0cface7c1..01dd0bcfd2 100644
--- a/src/OpenFOAM/containers/HashTables/HashTable/HashTable.C
+++ b/src/OpenFOAM/containers/HashTables/HashTable/HashTable.C
@@ -36,6 +36,16 @@ License
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
+template<class T, class Key, class Hash>
+Foam::HashTable<T, Key, Hash>::HashTable(const Foam::zero) noexcept
+:
+    HashTableCore(),
+    size_(0),
+    capacity_(0),
+    table_(nullptr)
+{}
+
+
 template<class T, class Key, class Hash>
 Foam::HashTable<T, Key, Hash>::HashTable()
 :
@@ -44,16 +54,19 @@ Foam::HashTable<T, Key, Hash>::HashTable()
 
 
 template<class T, class Key, class Hash>
-Foam::HashTable<T, Key, Hash>::HashTable(const label size)
+Foam::HashTable<T, Key, Hash>::HashTable(const label initialCapacity)
 :
     HashTableCore(),
     size_(0),
-    capacity_(HashTableCore::canonicalSize(size)),
+    capacity_(0),
     table_(nullptr)
 {
-    if (capacity_)
+    if (initialCapacity > 0)
     {
+        // Like resize() but no initial content to transfer
+        capacity_ = HashTableCore::canonicalSize(initialCapacity);
         table_ = new node_type*[capacity_];
+
         for (label i=0; i < capacity_; ++i)
         {
             table_[i] = nullptr;
@@ -75,13 +88,14 @@ Foam::HashTable<T, Key, Hash>::HashTable(const HashTable<T, Key, Hash>& ht)
 
 
 template<class T, class Key, class Hash>
-Foam::HashTable<T, Key, Hash>::HashTable(HashTable<T, Key, Hash>&& rhs)
+Foam::HashTable<T, Key, Hash>::HashTable(HashTable<T, Key, Hash>&& rhs) noexcept
 :
     HashTableCore(),
     size_(rhs.size_),
     capacity_(rhs.capacity_),
     table_(rhs.table_)
 {
+    // Stole all contents
     rhs.size_ = 0;
     rhs.capacity_ = 0;
     rhs.table_ = nullptr;
@@ -108,11 +122,13 @@ Foam::HashTable<T, Key, Hash>::HashTable
 template<class T, class Key, class Hash>
 Foam::HashTable<T, Key, Hash>::~HashTable()
 {
-    if (table_)
-    {
-        clear();
-        delete[] table_;
-    }
+    // Remove all entries from table
+    clear();
+
+    // Remove the table itself
+    capacity_ = 0;
+    delete[] table_;
+    table_ = nullptr;
 }
 
 
@@ -636,9 +652,9 @@ Foam::label Foam::HashTable<T, Key, Hash>::retain
 
 
 template<class T, class Key, class Hash>
-void Foam::HashTable<T, Key, Hash>::resize(const label sz)
+void Foam::HashTable<T, Key, Hash>::resize(const label requestedCapacity)
 {
-    const label newCapacity = HashTableCore::canonicalSize(sz);
+    const label newCapacity = HashTableCore::canonicalSize(requestedCapacity);
     const label oldCapacity = capacity_;
 
     if (newCapacity == oldCapacity)
@@ -656,12 +672,8 @@ void Foam::HashTable<T, Key, Hash>::resize(const label sz)
         }
         else
         {
-            if (table_)
-            {
-                delete[] table_;
-                capacity_ = 0;
-            }
-
+            capacity_ = 0;
+            delete[] table_;
             table_ = nullptr;
         }
 
@@ -679,9 +691,14 @@ void Foam::HashTable<T, Key, Hash>::resize(const label sz)
         table_[i] = nullptr;
     }
 
+    if (!oldTable)
+    {
+        return;
+    }
+
     // Move to new table[] but with new chaining.
 
-    for (label i = 0, nPending = size_; nPending && i < oldCapacity; ++i)
+    for (label i = 0, pending = size_; pending && i < oldCapacity; ++i)
     {
         for (node_type* ep = oldTable[i]; ep; /*nil*/)
         {
@@ -696,22 +713,24 @@ void Foam::HashTable<T, Key, Hash>::resize(const label sz)
             }
 
             ep = next;      // continue in the linked-list
-            --nPending;     // note any early completion
+            --pending;      // note any early completion
         }
         oldTable[i] = nullptr;
     }
 
-    if (oldTable)
-    {
-        delete[] oldTable;
-    }
+    delete[] oldTable;
 }
 
 
 template<class T, class Key, class Hash>
 void Foam::HashTable<T, Key, Hash>::clear()
 {
-    for (label i=0; size_ && i<capacity_; ++i)
+    if (!table_)
+    {
+        capacity_ = 0;  // Paranoid
+    }
+
+    for (label i = 0, pending = size_; pending && i < capacity_; ++i)
     {
         for (node_type* ep = table_[i]; ep; /*nil*/)
         {
@@ -720,23 +739,29 @@ void Foam::HashTable<T, Key, Hash>::clear()
             delete ep;
 
             ep = next;  // continue in the linked-list
-            --size_;    // note any early completion
+            --pending;  // note any early completion
         }
         table_[i] = nullptr;
     }
+    size_ = 0;
 }
 
 
 template<class T, class Key, class Hash>
 void Foam::HashTable<T, Key, Hash>::clearStorage()
 {
+    // Remove all entries from table
     clear();
-    resize(0);
+
+    // Remove the table itself
+    capacity_ = 0;
+    delete[] table_;
+    table_ = nullptr;
 }
 
 
 template<class T, class Key, class Hash>
-void Foam::HashTable<T, Key, Hash>::swap(HashTable<T, Key, Hash>& rhs)
+void Foam::HashTable<T, Key, Hash>::swap(HashTable<T, Key, Hash>& rhs) noexcept
 {
     if (this == &rhs)
     {
@@ -942,12 +967,7 @@ void Foam::HashTable<T, Key, Hash>::operator=
     HashTable<T, Key, Hash>&& rhs
 )
 {
-    if (this == &rhs)
-    {
-        return;  // Self-assignment is a no-op
-    }
-
-    transfer(rhs);
+    transfer(rhs);  // Includes self-assignment check
 }
 
 
@@ -994,7 +1014,7 @@ Foam::HashTable<T, Key, Hash>& Foam::HashTable<T, Key, Hash>::operator+=
 )
 {
     // Avoid no-ops:
-    if (rhs.size() || this != &rhs)
+    if (rhs.size() && (this != &rhs))
     {
         if (this->size())
         {
diff --git a/src/OpenFOAM/containers/HashTables/HashTable/HashTable.H b/src/OpenFOAM/containers/HashTables/HashTable/HashTable.H
index 4becd58ebe..6879d890e1 100644
--- a/src/OpenFOAM/containers/HashTables/HashTable/HashTable.H
+++ b/src/OpenFOAM/containers/HashTables/HashTable/HashTable.H
@@ -228,20 +228,24 @@ public:
 
     // Constructors
 
-        //- Default construct with default (128) table capacity
+        //- Default construct with default (128) initial table capacity
         HashTable();
 
-        //- Construct given initial table capacity
-        explicit HashTable(const label size);
+        //- Construct empty with zero initial table capacity
+        explicit HashTable(const Foam::zero) noexcept;
 
-        //- Construct from Istream with default table capacity
-        HashTable(Istream& is, const label size = 128);
+        //- Construct empty with initial table capacity
+        explicit HashTable(const label initialCapacity);
+
+        //- Construct from Istream,
+        //- with default or specified initial table capacity.
+        HashTable(Istream& is, const label initialCapacity = 128);
 
         //- Copy construct
         HashTable(const this_type& ht);
 
         //- Move construct
-        HashTable(this_type&& rhs);
+        HashTable(this_type&& rhs) noexcept;
 
         //- Construct from an initializer list
         //  Duplicate entries are handled by overwriting
@@ -528,17 +532,17 @@ public:
 
 
         //- Resize the hash table for efficiency
-        void resize(const label sz);
+        void resize(const label requestedCapacity);
 
-        //- Clear all entries from table
+        //- Remove all entries from table
         void clear();
 
-        //- Clear the table entries and the table itself.
+        //- Remove all entries from table and the table itself.
         //  Equivalent to clear() followed by resize(0)
         void clearStorage();
 
         //- Swap contents into this table
-        void swap(HashTable<T, Key, Hash>& rhs);
+        void swap(HashTable<T, Key, Hash>& rhs) noexcept;
 
         //- Transfer contents into this table.
         void transfer(HashTable<T, Key, Hash>& rhs);
diff --git a/src/OpenFOAM/containers/HashTables/HashTable/HashTableIO.C b/src/OpenFOAM/containers/HashTables/HashTable/HashTableIO.C
index 35c7b90d2a..3680f25aee 100644
--- a/src/OpenFOAM/containers/HashTables/HashTable/HashTableIO.C
+++ b/src/OpenFOAM/containers/HashTables/HashTable/HashTableIO.C
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2017-2021 OpenCFD Ltd.
+    Copyright (C) 2017-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -33,23 +33,14 @@ License
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
 template<class T, class Key, class Hash>
-Foam::HashTable<T, Key, Hash>::HashTable(Istream& is, const label size)
+Foam::HashTable<T, Key, Hash>::HashTable
+(
+    Istream& is,
+    const label initialCapacity
+)
 :
-    HashTableCore(),
-    size_(0),
-    capacity_(HashTableCore::canonicalSize(size)),
-    table_(nullptr)
+    HashTable(initialCapacity)
 {
-    if (capacity_)
-    {
-        table_ = new node_type*[capacity_];
-
-        for (label i=0; i < capacity_; ++i)
-        {
-            table_[i] = nullptr;
-        }
-    }
-
     operator>>(is, *this);
 }
 
diff --git a/src/OpenFOAM/containers/HashTables/Map/Map.H b/src/OpenFOAM/containers/HashTables/Map/Map.H
index fe10faf945..4866e954b8 100644
--- a/src/OpenFOAM/containers/HashTables/Map/Map.H
+++ b/src/OpenFOAM/containers/HashTables/Map/Map.H
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2017 OpenCFD Ltd.
+    Copyright (C) 2017-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -73,19 +73,22 @@ public:
 
     // Constructors
 
-        //- Default construct with default table capacity
-        Map()
+        //- Default construct with default (128) initial table capacity
+        Map() = default;
+
+        //- Construct empty with zero initial table capacity
+        explicit Map(const Foam::zero) noexcept
         :
-            parent_type()
+            parent_type(Foam::zero{})
         {}
 
-        //- Construct with given initial table capacity
-        explicit Map(const label size)
+        //- Construct empty with given initial table capacity
+        explicit Map(const label initialCapacity)
         :
-            parent_type(size)
+            parent_type(initialCapacity)
         {}
 
-        //- Construct from Istream with default table capacity
+        //- Construct from Istream (with default initial table capacity)
         Map(Istream& is)
         :
             parent_type(is)
@@ -98,7 +101,7 @@ public:
         {}
 
         //- Move construct
-        Map(this_type&& map)
+        Map(this_type&& map) noexcept
         :
             parent_type(std::move(map))
         {}
diff --git a/src/OpenFOAM/containers/HashTables/PtrMap/PtrMap.H b/src/OpenFOAM/containers/HashTables/PtrMap/PtrMap.H
index 2313fd5205..3d3d08b532 100644
--- a/src/OpenFOAM/containers/HashTables/PtrMap/PtrMap.H
+++ b/src/OpenFOAM/containers/HashTables/PtrMap/PtrMap.H
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2017-2018 OpenCFD Ltd.
+    Copyright (C) 2017-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -65,19 +65,22 @@ public:
 
     // Constructors
 
-        //- Default construct with default table capacity
-        PtrMap()
+        //- Default construct with default (128) initial table capacity
+        PtrMap() = default;
+
+        //- Construct empty with zero initial table capacity
+        explicit PtrMap(const Foam::zero) noexcept
         :
-            parent_type()
+            parent_type(Foam::zero{})
         {}
 
-        //- Construct with given initial table capacity
-        explicit PtrMap(const label size)
+        //- Construct empty with given initial table capacity
+        explicit PtrMap(const label initialCapacity)
         :
-            parent_type(size)
+            parent_type(initialCapacity)
         {}
 
-        //- Construct from Istream
+        //- Construct from Istream (with default initial table capacity)
         PtrMap(Istream& is)
         :
             parent_type(is)
@@ -90,7 +93,7 @@ public:
         {}
 
         //- Move construct
-        PtrMap(this_type&& map)
+        PtrMap(this_type&& map) noexcept
         :
             parent_type(std::move(map))
         {}
diff --git a/src/OpenFOAM/containers/Lists/DynamicList/DynamicList.H b/src/OpenFOAM/containers/Lists/DynamicList/DynamicList.H
index 46fae4d5e7..9d208adec6 100644
--- a/src/OpenFOAM/containers/Lists/DynamicList/DynamicList.H
+++ b/src/OpenFOAM/containers/Lists/DynamicList/DynamicList.H
@@ -113,8 +113,8 @@ public:
         //- Default construct, an empty list without allocation.
         inline constexpr DynamicList() noexcept;
 
-        //- Construct an empty list with given reserve size.
-        inline explicit DynamicList(const label len);
+        //- Construct an empty list with given initial capacity
+        inline explicit DynamicList(const label initialCapacity);
 
         //- Construct with given size and value for all elements.
         inline DynamicList(const label len, const T& val);
diff --git a/src/OpenFOAM/containers/Lists/DynamicList/DynamicListI.H b/src/OpenFOAM/containers/Lists/DynamicList/DynamicListI.H
index ccf07d15a5..595ef3b828 100644
--- a/src/OpenFOAM/containers/Lists/DynamicList/DynamicListI.H
+++ b/src/OpenFOAM/containers/Lists/DynamicList/DynamicListI.H
@@ -143,12 +143,12 @@ inline constexpr Foam::DynamicList<T, SizeMin>::DynamicList() noexcept
 
 
 template<class T, int SizeMin>
-inline Foam::DynamicList<T, SizeMin>::DynamicList(const label len)
+inline Foam::DynamicList<T, SizeMin>::DynamicList(const label initialCapacity)
 :
     List<T>(),
     capacity_(0)
 {
-    reserve_nocopy(len);
+    reserve_nocopy(initialCapacity);
 }
 
 
diff --git a/src/OpenFOAM/db/IOobjectList/IOobjectList.H b/src/OpenFOAM/db/IOobjectList/IOobjectList.H
index a108b17687..5c951c4ec5 100644
--- a/src/OpenFOAM/db/IOobjectList/IOobjectList.H
+++ b/src/OpenFOAM/db/IOobjectList/IOobjectList.H
@@ -168,10 +168,13 @@ public:
     // Constructors
 
         //- Default construct (empty) with default (128) table capacity
-        inline IOobjectList();
+        IOobjectList() = default;
+
+        //- Construct with zero table capacity
+        inline explicit IOobjectList(const Foam::zero) noexcept;
 
         //- Construct given initial table capacity
-        inline explicit IOobjectList(const label nObjects);
+        inline explicit IOobjectList(const label initialCapacity);
 
         //- Copy construct
         inline IOobjectList(const IOobjectList& list);
diff --git a/src/OpenFOAM/db/IOobjectList/IOobjectListI.H b/src/OpenFOAM/db/IOobjectList/IOobjectListI.H
index e9f90e6361..9408e7b53a 100644
--- a/src/OpenFOAM/db/IOobjectList/IOobjectListI.H
+++ b/src/OpenFOAM/db/IOobjectList/IOobjectListI.H
@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2022 OpenCFD Ltd.
+    Copyright (C) 2022-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -27,15 +27,15 @@ License
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
-inline Foam::IOobjectList::IOobjectList()
+inline Foam::IOobjectList::IOobjectList(const Foam::zero) noexcept
 :
-    HashPtrTable<IOobject>()
+    HashPtrTable<IOobject>(Foam::zero{})
 {}
 
 
-inline Foam::IOobjectList::IOobjectList(const label nObjects)
+inline Foam::IOobjectList::IOobjectList(const label initialCapacity)
 :
-    HashPtrTable<IOobject>(nObjects)  // Could also use 2*nObjects instead
+    HashPtrTable<IOobject>(initialCapacity)
 {}
 
 
diff --git a/src/OpenFOAM/db/objectRegistry/objectRegistry.C b/src/OpenFOAM/db/objectRegistry/objectRegistry.C
index 9e33ec1fe1..df993fd902 100644
--- a/src/OpenFOAM/db/objectRegistry/objectRegistry.C
+++ b/src/OpenFOAM/db/objectRegistry/objectRegistry.C
@@ -79,7 +79,11 @@ bool Foam::objectRegistry::parentNotTime() const noexcept
 
 // * * * * * * * * * * * * * * * * Constructors *  * * * * * * * * * * * * * //
 
-Foam::objectRegistry::objectRegistry(const Time& t, const label nObjects)
+Foam::objectRegistry::objectRegistry
+(
+    const Time& t,
+    const label initialCapacity
+)
 :
     regIOobject
     (
@@ -94,7 +98,7 @@ Foam::objectRegistry::objectRegistry(const Time& t, const label nObjects)
         ),
         true    // to flag that this is the top-level regIOobject
     ),
-    HashTable<regIOobject*>(nObjects),
+    HashTable<regIOobject*>(initialCapacity),
     time_(t),
     parent_(t),
     dbDir_(name()),
@@ -105,10 +109,14 @@ Foam::objectRegistry::objectRegistry(const Time& t, const label nObjects)
 {}
 
 
-Foam::objectRegistry::objectRegistry(const IOobject& io, const label nObjects)
+Foam::objectRegistry::objectRegistry
+(
+    const IOobject& io,
+    const label initialCapacity
+)
 :
     regIOobject(io),
-    HashTable<regIOobject*>(nObjects),
+    HashTable<regIOobject*>(initialCapacity),
     time_(io.time()),
     parent_(io.db()),
     dbDir_(parent_.dbDir()/local()/name()),
@@ -117,7 +125,7 @@ Foam::objectRegistry::objectRegistry(const IOobject& io, const label nObjects)
     cacheTemporaryObjects_(0),
     temporaryObjects_(0)
 {
-    writeOpt(IOobject::AUTO_WRITE);
+    writeOpt(IOobjectOption::AUTO_WRITE);
 }
 
 
diff --git a/src/OpenFOAM/db/objectRegistry/objectRegistry.H b/src/OpenFOAM/db/objectRegistry/objectRegistry.H
index 5216ce223d..9ae0c9e868 100644
--- a/src/OpenFOAM/db/objectRegistry/objectRegistry.H
+++ b/src/OpenFOAM/db/objectRegistry/objectRegistry.H
@@ -177,11 +177,19 @@ public:
 
         //- Construct the time objectRegistry,
         //- with estimated table capacity (default: 128)
-        explicit objectRegistry(const Time& db, const label nObjects=128);
+        explicit objectRegistry
+        (
+            const Time& db,
+            const label initialCapacity = 128
+        );
 
         //- Construct sub-registry given an IObject to describe the registry,
         //- with estimated table capacity (default: 128)
-        explicit objectRegistry(const IOobject& io, const label nObjects=128);
+        explicit objectRegistry
+        (
+            const IOobject& io,
+            const label initialCapacity = 128
+        );
 
 
     //- Destructor, with checkOut() for all objects that are ownedByRegistry
diff --git a/src/OpenFOAM/fields/Fields/DynamicField/DynamicField.H b/src/OpenFOAM/fields/Fields/DynamicField/DynamicField.H
index 57cffa452b..74b8a5c7e0 100644
--- a/src/OpenFOAM/fields/Fields/DynamicField/DynamicField.H
+++ b/src/OpenFOAM/fields/Fields/DynamicField/DynamicField.H
@@ -109,8 +109,8 @@ public:
         //- Default construct, an empty field without allocation.
         inline constexpr DynamicField() noexcept;
 
-        //- Construct empty field with given reserve size.
-        inline explicit DynamicField(const label len);
+        //- Construct empty field with given initial capacity
+        inline explicit DynamicField(const label initialCapacity);
 
         //- Construct given size and initial value
         inline DynamicField(const label len, const T& val);
diff --git a/src/OpenFOAM/fields/Fields/DynamicField/DynamicFieldI.H b/src/OpenFOAM/fields/Fields/DynamicField/DynamicFieldI.H
index b96d88d268..a2c15434fb 100644
--- a/src/OpenFOAM/fields/Fields/DynamicField/DynamicFieldI.H
+++ b/src/OpenFOAM/fields/Fields/DynamicField/DynamicFieldI.H
@@ -137,12 +137,12 @@ inline constexpr Foam::DynamicField<T, SizeMin>::DynamicField() noexcept
 
 
 template<class T, int SizeMin>
-inline Foam::DynamicField<T, SizeMin>::DynamicField(const label len)
+inline Foam::DynamicField<T, SizeMin>::DynamicField(const label initialCapacity)
 :
     Field<T>(),
     capacity_(0)
 {
-    reserve_nocopy(len);
+    reserve_nocopy(initialCapacity);
 }