diff --git a/applications/utilities/mesh/manipulation/setSet/setSet.C b/applications/utilities/mesh/manipulation/setSet/setSet.C
index 8a2d0a16e5..86f4880a6c 100644
--- a/applications/utilities/mesh/manipulation/setSet/setSet.C
+++ b/applications/utilities/mesh/manipulation/setSet/setSet.C
@@ -887,7 +887,7 @@ int main(int argc, char *argv[])
             Info<< "Reading commands from file " << batchFile << endl;
 
             // we cannot handle .gz files
-            if (!isFile(batchFile, false))
+            if (!isFile(batchFile, false, false))
             {
                 FatalErrorInFunction
                     << "Cannot open file " << batchFile << exit(FatalError);
diff --git a/src/OSspecific/POSIX/POSIX.C b/src/OSspecific/POSIX/POSIX.C
index 2046a91393..b8392a936e 100644
--- a/src/OSspecific/POSIX/POSIX.C
+++ b/src/OSspecific/POSIX/POSIX.C
@@ -456,7 +456,12 @@ bool Foam::chMod(const fileName& name, const mode_t m)
 }
 
 
-mode_t Foam::mode(const fileName& name, const bool followLink)
+mode_t Foam::mode
+(
+    const fileName& name,
+    const bool checkVariants,
+    const bool followLink
+)
 {
     if (POSIX::debug)
     {
@@ -466,7 +471,7 @@ mode_t Foam::mode(const fileName& name, const bool followLink)
             error::printStack(Pout);
         }
     }
-    fileStat fileStatus(name, followLink);
+    fileStat fileStatus(name, checkVariants, followLink);
     if (fileStatus.isValid())
     {
         return fileStatus.status().st_mode;
@@ -478,13 +483,18 @@ mode_t Foam::mode(const fileName& name, const bool followLink)
 }
 
 
-Foam::fileName::Type Foam::type(const fileName& name, const bool followLink)
+Foam::fileName::Type Foam::type
+(
+    const fileName& name,
+    const bool checkVariants,
+    const bool followLink
+)
 {
     if (POSIX::debug)
     {
         Pout<< FUNCTION_NAME << " : name:" << name << endl;
     }
-    mode_t m = mode(name, followLink);
+    mode_t m = mode(name, checkVariants, followLink);
 
     if (S_ISREG(m))
     {
@@ -508,20 +518,20 @@ Foam::fileName::Type Foam::type(const fileName& name, const bool followLink)
 bool Foam::exists
 (
     const fileName& name,
-    const bool checkGzip,
+    const bool checkVariants,
     const bool followLink
 )
 {
     if (POSIX::debug)
     {
-        Pout<< FUNCTION_NAME << " : name:" << name << " checkGzip:" << checkGzip
-            << endl;
+        Pout<< FUNCTION_NAME << " : name:" << name << " checkVariants:"
+            << bool(checkVariants) << " followLink:" << followLink << endl;
         if ((POSIX::debug & 2) && !Pstream::master())
         {
             error::printStack(Pout);
         }
     }
-    return mode(name, followLink) || isFile(name, checkGzip, followLink);
+    return mode(name, checkVariants, followLink);
 }
 
 
@@ -529,51 +539,55 @@ bool Foam::isDir(const fileName& name, const bool followLink)
 {
     if (POSIX::debug)
     {
-        Pout<< FUNCTION_NAME << " : name:" << name << endl;
+        Pout<< FUNCTION_NAME << " : name:" << name << " followLink:"
+            << followLink << endl;
         if ((POSIX::debug & 2) && !Pstream::master())
         {
             error::printStack(Pout);
         }
     }
-    return S_ISDIR(mode(name, followLink));
+    return S_ISDIR(mode(name, false, followLink));
 }
 
 
 bool Foam::isFile
 (
     const fileName& name,
-    const bool checkGzip,
+    const bool checkVariants,
     const bool followLink
 )
 {
     if (POSIX::debug)
     {
-        Pout<< FUNCTION_NAME << " : name:" << name << " checkGzip:" << checkGzip
-            << endl;
+        Pout<< FUNCTION_NAME << " : name:" << name << " checkVariants:"
+            << bool(checkVariants) << " followLink:" << followLink << endl;
         if ((POSIX::debug & 2) && !Pstream::master())
         {
             error::printStack(Pout);
         }
     }
 
-    return
-        S_ISREG(mode(name, followLink))
-     || (checkGzip && S_ISREG(mode(name + ".gz", followLink)))
-     || (checkGzip && S_ISREG(mode(name + ".orig", followLink)));
+    return S_ISREG(mode(name, checkVariants, followLink));
 }
 
 
-off_t Foam::fileSize(const fileName& name, const bool followLink)
+off_t Foam::fileSize
+(
+    const fileName& name,
+    const bool checkVariants,
+    const bool followLink
+)
 {
     if (POSIX::debug)
     {
-        Pout<< FUNCTION_NAME << " : name:" << name << endl;
+        Pout<< FUNCTION_NAME << " : name:" << name << " checkVariants:"
+            << bool(checkVariants) << " followLink:" << followLink << endl;
         if ((POSIX::debug & 2) && !Pstream::master())
         {
             error::printStack(Pout);
         }
     }
-    fileStat fileStatus(name, followLink);
+    fileStat fileStatus(name, checkVariants, followLink);
     if (fileStatus.isValid())
     {
         return fileStatus.status().st_size;
@@ -585,17 +599,23 @@ off_t Foam::fileSize(const fileName& name, const bool followLink)
 }
 
 
-time_t Foam::lastModified(const fileName& name, const bool followLink)
+time_t Foam::lastModified
+(
+    const fileName& name,
+    const bool checkVariants,
+    const bool followLink
+)
 {
     if (POSIX::debug)
     {
-        Pout<< FUNCTION_NAME << " : name:" << name << endl;
+        Pout<< FUNCTION_NAME << " : name:" << name << " checkVariants:"
+            << bool(checkVariants) << " followLink:" << followLink << endl;
         if ((POSIX::debug & 2) && !Pstream::master())
         {
             error::printStack(Pout);
         }
     }
-    fileStat fileStatus(name, followLink);
+    fileStat fileStatus(name, checkVariants, followLink);
     if (fileStatus.isValid())
     {
         return fileStatus.status().st_mtime;
@@ -607,17 +627,23 @@ time_t Foam::lastModified(const fileName& name, const bool followLink)
 }
 
 
-double Foam::highResLastModified(const fileName& name, const bool followLink)
+double Foam::highResLastModified
+(
+    const fileName& name,
+    const bool checkVariants,
+    const bool followLink
+)
 {
     if (POSIX::debug)
     {
-        Pout<< FUNCTION_NAME << " : name:" << name << endl;
+        Pout<< FUNCTION_NAME << " : name:" << name << " checkVariants:"
+            << bool(checkVariants) << " followLink:" << followLink << endl;
         if ((POSIX::debug & 2) && !Pstream::master())
         {
             error::printStack(Pout);
         }
     }
-    fileStat fileStatus(name, followLink);
+    fileStat fileStatus(name, checkVariants, followLink);
     if (fileStatus.isValid())
     {
         return
@@ -635,7 +661,7 @@ Foam::fileNameList Foam::readDir
 (
     const fileName& directory,
     const fileName::Type type,
-    const bool filtergz,
+    const bool filterVariants,
     const bool followLink
 )
 {
@@ -700,24 +726,25 @@ Foam::fileNameList Foam::readDir
                     )
                 )
                 {
-                    if ((directory/fName).type(followLink) == type)
+                    if ((directory/fName).type(false, followLink) == type)
                     {
                         if (nEntries >= dirEntries.size())
                         {
                             dirEntries.setSize(dirEntries.size() + maxNnames);
                         }
 
-                        if (filtergz && fExt == "gz")
+                        dirEntries[nEntries++] = fName;
+
+                        if (filterVariants)
                         {
-                            dirEntries[nEntries++] = fName.lessExt();
-                        }
-                        else if (filtergz && fExt == "orig")
-                        {
-                            dirEntries[nEntries++] = fName.lessExt();
-                        }
-                        else
-                        {
-                            dirEntries[nEntries++] = fName;
+                            for (label i = 0; i < fileStat::nVariants_; ++ i)
+                            {
+                                if (fExt == fileStat::variantExts_[i])
+                                {
+                                    dirEntries[nEntries - 1] = fName.lessExt();
+                                    break;
+                                }
+                            }
                         }
                     }
                 }
@@ -750,7 +777,7 @@ bool Foam::cp(const fileName& src, const fileName& dest, const bool followLink)
         return false;
     }
 
-    const fileName::Type srcType = src.type(followLink);
+    const fileName::Type srcType = src.type(false, followLink);
 
     fileName destFile(dest);
 
@@ -949,7 +976,7 @@ bool Foam::mv(const fileName& src, const fileName& dst, const bool followLink)
     if
     (
         dst.type() == fileName::DIRECTORY
-     && src.type(followLink) != fileName::DIRECTORY
+     && src.type(false, followLink) != fileName::DIRECTORY
     )
     {
         const fileName dstName(dst/src.name());
@@ -976,7 +1003,7 @@ bool Foam::mvBak(const fileName& src, const std::string& ext)
         }
     }
 
-    if (exists(src, false))
+    if (exists(src, false, false))
     {
         const int maxIndex = 99;
         char index[3];
@@ -992,7 +1019,7 @@ bool Foam::mvBak(const fileName& src, const std::string& ext)
 
             // avoid overwriting existing files, except for the last
             // possible index where we have no choice
-            if (!exists(dstName, false) || n == maxIndex)
+            if (!exists(dstName, false, false) || n == maxIndex)
             {
                 return ::rename(src.c_str(), dstName.c_str()) == 0;
             }
@@ -1017,15 +1044,22 @@ bool Foam::rm(const fileName& file)
         }
     }
 
-    // Try returning plain file name; if not there, try with .gz
+    // Try returning plain file name; if not there, try variants
     if (remove(file.c_str()) == 0)
     {
         return true;
     }
-    else
+
+    for (label i = 0; i < fileStat::nVariants_; ++ i)
     {
-        return ::remove(string(file + ".gz").c_str()) == 0;
+        const fileName fileVar = file + "." + fileStat::variantExts_[i];
+        if (::remove(string(fileVar).c_str()) == 0)
+        {
+            return true;
+        }
     }
+
+    return false;
 }
 
 
@@ -1064,7 +1098,7 @@ bool Foam::rmDir(const fileName& directory)
             {
                 fileName path = directory/fName;
 
-                if (path.type(false) == fileName::DIRECTORY)
+                if (path.type(false, false) == fileName::DIRECTORY)
                 {
                     if (!rmDir(path))
                     {
diff --git a/src/OSspecific/POSIX/fileStat.C b/src/OSspecific/POSIX/fileStat.C
index 7f40e0637f..ffb26041ca 100644
--- a/src/OSspecific/POSIX/fileStat.C
+++ b/src/OSspecific/POSIX/fileStat.C
@@ -31,6 +31,13 @@ License
 #include <unistd.h>
 #include <sys/sysmacros.h>
 
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+const Foam::label Foam::fileStat::nVariants_ = 2;
+
+const char* Foam::fileStat::variantExts_[] = {"gz", "orig"};
+
+
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
 Foam::fileStat::fileStat()
@@ -42,6 +49,7 @@ Foam::fileStat::fileStat()
 Foam::fileStat::fileStat
 (
     const fileName& fName,
+    const bool checkVariants,
     const bool followLink,
     const unsigned int maxTime
 )
@@ -53,26 +61,22 @@ Foam::fileStat::fileStat
 
     if (!timedOut(myTimer))
     {
-        if (followLink)
+        int (*getFileStatus)(const char *, struct stat *) =
+            followLink ? ::stat : ::lstat;
+
+        if (getFileStatus(fName.c_str(), &status_) == 0)
         {
-            if (::stat(fName.c_str(), &status_) != 0)
-            {
-                locIsValid = false;
-            }
-            else
-            {
-                locIsValid = true;
-            }
+            locIsValid = true;
         }
-        else
+        else if (checkVariants)
         {
-            if (::lstat(fName.c_str(), &status_) != 0)
+            for (label i = 0; !locIsValid && i < nVariants_; ++ i)
             {
-                locIsValid = false;
-            }
-            else
-            {
-                locIsValid = true;
+                const fileName fNameVar = fName + "." + variantExts_[i];
+                if (getFileStatus(fNameVar.c_str(), &status_) == 0)
+                {
+                    locIsValid = true;
+                }
             }
         }
     }
diff --git a/src/OSspecific/POSIX/fileStat.H b/src/OSspecific/POSIX/fileStat.H
index ba089dffe0..ff32faf64a 100644
--- a/src/OSspecific/POSIX/fileStat.H
+++ b/src/OSspecific/POSIX/fileStat.H
@@ -74,6 +74,15 @@ class fileStat
 
 public:
 
+    // Public static data
+
+        //- Number of file variants
+        static const label nVariants_;
+
+        //- Extensions of the file variants
+        static const char* variantExts_[];
+
+
     // Constructors
 
         //- Empty constructor
@@ -85,6 +94,7 @@ public:
         fileStat
         (
             const fileName& fName,
+            const bool checkVariants = true,
             const bool followLink = true,
             const unsigned int maxTime = 0
         );
diff --git a/src/OpenFOAM/db/IOstreams/Fstreams/IFstream.C b/src/OpenFOAM/db/IOstreams/Fstreams/IFstream.C
index bb502534e3..d17cbfa1a5 100644
--- a/src/OpenFOAM/db/IOstreams/Fstreams/IFstream.C
+++ b/src/OpenFOAM/db/IOstreams/Fstreams/IFstream.C
@@ -55,7 +55,7 @@ Foam::IFstreamAllocator::IFstreamAllocator(const fileName& pathname)
     // If the file is compressed, decompress it before reading.
     if (!ifPtr_->good())
     {
-        if (isFile(pathname + ".gz", false))
+        if (isFile(pathname + ".gz", false, false))
         {
             delete ifPtr_;
 
@@ -71,7 +71,7 @@ Foam::IFstreamAllocator::IFstreamAllocator(const fileName& pathname)
                 compression_ = IOstream::COMPRESSED;
             }
         }
-        else if (isFile(pathname + ".orig", false))
+        else if (isFile(pathname + ".orig", false, false))
         {
             delete ifPtr_;
 
@@ -174,8 +174,8 @@ Foam::IFstream& Foam::IFstream::operator()() const
 {
     if (!good())
     {
-        // also checks .gz file
-        if (isFile(pathname_, true))
+        // also checks variants
+        if (isFile(pathname_, true, true))
         {
             check("IFstream::operator()");
             FatalIOError.exit();
diff --git a/src/OpenFOAM/db/IOstreams/Fstreams/OFstream.C b/src/OpenFOAM/db/IOstreams/Fstreams/OFstream.C
index 64ca1eb403..3952d44aef 100644
--- a/src/OpenFOAM/db/IOstreams/Fstreams/OFstream.C
+++ b/src/OpenFOAM/db/IOstreams/Fstreams/OFstream.C
@@ -62,7 +62,7 @@ Foam::OFstreamAllocator::OFstreamAllocator
     if (compression == IOstream::COMPRESSED)
     {
         // Get identically named uncompressed version out of the way
-        fileName::Type pathType = Foam::type(pathname, false);
+        fileName::Type pathType = Foam::type(pathname, false, false);
         if (pathType == fileName::FILE || pathType == fileName::LINK)
         {
             rm(pathname);
@@ -82,12 +82,16 @@ Foam::OFstreamAllocator::OFstreamAllocator
     {
         // get identically named compressed version out of the way
         fileName gzPathName(pathname + ".gz");
-        fileName::Type gzType = Foam::type(gzPathName, false);
+        fileName::Type gzType = Foam::type(gzPathName, false, false);
         if (gzType == fileName::FILE || gzType == fileName::LINK)
         {
             rm(gzPathName);
         }
-        if (!append && Foam::type(pathname, false) == fileName::LINK)
+        if
+        (
+            !append
+         && Foam::type(pathname, false, false) == fileName::LINK
+        )
         {
             // Disallow writing into softlink to avoid any problems with
             // e.g. softlinked initial fields
diff --git a/src/OpenFOAM/db/Time/Time.C b/src/OpenFOAM/db/Time/Time.C
index 336b1d8871..0a8d04cf44 100644
--- a/src/OpenFOAM/db/Time/Time.C
+++ b/src/OpenFOAM/db/Time/Time.C
@@ -162,7 +162,7 @@ void Foam::Time::setControls()
 
     // Check if time directory exists
     // If not increase time precision to see if it is formatted differently.
-    if (!fileHandler().exists(timePath(), false))
+    if (!fileHandler().exists(timePath(), false, false))
     {
         int oldPrecision = precision_;
         int requiredPrecision = -1;
@@ -186,7 +186,7 @@ void Foam::Time::setControls()
             oldTime = newTime;
 
             // Check the existence of the time directory with the new format
-            found = fileHandler().exists(timePath(), false);
+            found = fileHandler().exists(timePath(), false, false);
 
             if (found)
             {
diff --git a/src/OpenFOAM/db/dynamicLibrary/dynamicCode/dynamicCode.C b/src/OpenFOAM/db/dynamicLibrary/dynamicCode/dynamicCode.C
index 1608063279..87e7fd07f2 100644
--- a/src/OpenFOAM/db/dynamicLibrary/dynamicCode/dynamicCode.C
+++ b/src/OpenFOAM/db/dynamicLibrary/dynamicCode/dynamicCode.C
@@ -157,7 +157,7 @@ bool Foam::dynamicCode::resolveTemplates
         if (!templateDir.empty() && isDir(templateDir))
         {
             file = templateDir/templateName;
-            if (!isFile(file, false))
+            if (!isFile(file, false, false))
             {
                 file.clear();
             }
@@ -512,7 +512,7 @@ bool Foam::dynamicCode::upToDate(const SHA1Digest& sha1) const
 {
     const fileName file = digestFile();
 
-    if (!exists(file, false) || SHA1Digest(IFstream(file)()) != sha1)
+    if (!exists(file, false, false) || SHA1Digest(IFstream(file)()) != sha1)
     {
         return false;
     }
diff --git a/src/OpenFOAM/global/fileOperations/fileOperation/fileOperation.H b/src/OpenFOAM/global/fileOperations/fileOperation/fileOperation.H
index 3f01a6e75a..79780ff319 100644
--- a/src/OpenFOAM/global/fileOperations/fileOperation/fileOperation.H
+++ b/src/OpenFOAM/global/fileOperations/fileOperation/fileOperation.H
@@ -198,6 +198,7 @@ public:
             virtual mode_t mode
             (
                 const fileName&,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const = 0;
 
@@ -205,6 +206,7 @@ public:
             virtual fileName::Type type
             (
                 const fileName&,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const = 0;
 
@@ -213,7 +215,7 @@ public:
             virtual bool exists
             (
                 const fileName&,
-                const bool checkGzip=true,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const = 0;
 
@@ -229,7 +231,7 @@ public:
             virtual bool isFile
             (
                 const fileName&,
-                const bool checkGzip=true,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const = 0;
 
@@ -237,6 +239,7 @@ public:
             virtual off_t fileSize
             (
                 const fileName&,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const = 0;
 
@@ -244,6 +247,7 @@ public:
             virtual time_t lastModified
             (
                 const fileName&,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const = 0;
 
@@ -251,6 +255,7 @@ public:
             virtual double highResLastModified
             (
                 const fileName&,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const = 0;
 
@@ -259,7 +264,7 @@ public:
             (
                 const fileName&,
                 const fileName::Type=fileName::FILE,
-                const bool filtergz=true,
+                const bool filterVariants = true,
                 const bool followLink = true
             ) const = 0;
 
diff --git a/src/OpenFOAM/global/fileOperations/masterUncollatedFileOperation/masterUncollatedFileOperation.C b/src/OpenFOAM/global/fileOperations/masterUncollatedFileOperation/masterUncollatedFileOperation.C
index e6efc0335a..d4ee8b67da 100644
--- a/src/OpenFOAM/global/fileOperations/masterUncollatedFileOperation/masterUncollatedFileOperation.C
+++ b/src/OpenFOAM/global/fileOperations/masterUncollatedFileOperation/masterUncollatedFileOperation.C
@@ -36,6 +36,7 @@ License
 #include "SubList.H"
 #include "unthreadedInitialise.H"
 #include "PackedBoolList.H"
+#include "gzstream.h"
 
 /* * * * * * * * * * * * * * * Static Member Data  * * * * * * * * * * * * * */
 
@@ -496,25 +497,28 @@ bool Foam::fileOperations::masterUncollatedFileOperation::uniformFile
 void Foam::fileOperations::masterUncollatedFileOperation::readAndSend
 (
     const fileName& filePath,
-    const IOstream::compressionType cmp,
     const labelUList& procs,
     PstreamBuffers& pBufs
 )
 {
-    if (cmp == IOstream::compressionType::COMPRESSED)
+    if (debug)
+    {
+        Pout<< FUNCTION_NAME << ": Opening " << filePath << endl;
+    }
+
+    IFstream is(filePath, IOstream::streamFormat::BINARY);
+
+    if (!is.good())
+    {
+        FatalIOErrorInFunction(filePath) << "Cannot open file " << filePath
+            << exit(FatalIOError);
+    }
+
+    if (isA<igzstream>(is.stdStream()))
     {
         if (debug)
         {
-            Pout<< "masterUncollatedFileOperation::readAndSend :"
-                << " Opening compressed " << filePath << endl;
-        }
-
-        IFstream is(filePath, IOstream::streamFormat::BINARY);
-
-        if (!is.good())
-        {
-            FatalIOErrorInFunction(filePath) << "Cannot open file " << filePath
-                << exit(FatalIOError);
+            Pout<< FUNCTION_NAME << ": Reading compressed" << endl;
         }
 
         std::ostringstream stringStr;
@@ -530,21 +534,12 @@ void Foam::fileOperations::masterUncollatedFileOperation::readAndSend
     else
     {
         off_t count(Foam::fileSize(filePath));
-        IFstream is(filePath, IOstream::streamFormat::BINARY);
-
-        if (!is.good())
-        {
-            FatalIOErrorInFunction(filePath) << "Cannot open file " << filePath
-                << exit(FatalIOError);
-        }
-
 
         if (debug)
         {
-            Pout<< "masterUncollatedFileOperation::readStream :"
-                << " From " << filePath <<  " reading " << label(count)
-                << " bytes" << endl;
+            Pout<< FUNCTION_NAME << " : Reading " << count << " bytes " << endl;
         }
+
         List<char> buf(static_cast<label>(count));
         is.stdStream().read(buf.begin(), count);
 
@@ -557,36 +552,6 @@ void Foam::fileOperations::masterUncollatedFileOperation::readAndSend
 }
 
 
-void Foam::fileOperations::masterUncollatedFileOperation::readAndSend
-(
-    const fileName& fName,
-    const labelUList& procs,
-    PstreamBuffers& pBufs
-)
-{
-    if (Foam::exists(fName+".gz", false))
-    {
-        readAndSend
-        (
-            fName,
-            IOstream::compressionType::COMPRESSED,
-            procs,
-            pBufs
-        );
-    }
-    else
-    {
-        readAndSend
-        (
-            fName,
-            IOstream::compressionType::UNCOMPRESSED,
-            procs,
-            pBufs
-        );
-    }
-}
-
-
 Foam::autoPtr<Foam::ISstream>
 Foam::fileOperations::masterUncollatedFileOperation::read
 (
@@ -910,13 +875,14 @@ bool Foam::fileOperations::masterUncollatedFileOperation::chMod
 mode_t Foam::fileOperations::masterUncollatedFileOperation::mode
 (
     const fileName& fName,
+    const bool checkVariants,
     const bool followLink
 ) const
 {
     return masterOp<mode_t, modeOp>
     (
         fName,
-        modeOp(followLink),
+        modeOp(checkVariants, followLink),
         Pstream::msgType(),
         comm_
     );
@@ -926,6 +892,7 @@ mode_t Foam::fileOperations::masterUncollatedFileOperation::mode
 Foam::fileName::Type Foam::fileOperations::masterUncollatedFileOperation::type
 (
     const fileName& fName,
+    const bool checkVariants,
     const bool followLink
 ) const
 {
@@ -934,7 +901,7 @@ Foam::fileName::Type Foam::fileOperations::masterUncollatedFileOperation::type
         masterOp<label, typeOp>
         (
             fName,
-            typeOp(followLink),
+            typeOp(checkVariants, followLink),
             Pstream::msgType(),
             comm_
         )
@@ -945,14 +912,14 @@ Foam::fileName::Type Foam::fileOperations::masterUncollatedFileOperation::type
 bool Foam::fileOperations::masterUncollatedFileOperation::exists
 (
     const fileName& fName,
-    const bool checkGzip,
+    const bool checkVariants,
     const bool followLink
 ) const
 {
     return masterOp<bool, existsOp>
     (
         fName,
-        existsOp(checkGzip, followLink),
+        existsOp(checkVariants, followLink),
         Pstream::msgType(),
         comm_
     );
@@ -978,14 +945,14 @@ bool Foam::fileOperations::masterUncollatedFileOperation::isDir
 bool Foam::fileOperations::masterUncollatedFileOperation::isFile
 (
     const fileName& fName,
-    const bool checkGzip,
+    const bool checkVariants,
     const bool followLink
 ) const
 {
     return masterOp<bool, isFileOp>
     (
         fName,
-        isFileOp(checkGzip, followLink),
+        isFileOp(checkVariants, followLink),
         Pstream::msgType(),
         comm_
     );
@@ -995,13 +962,14 @@ bool Foam::fileOperations::masterUncollatedFileOperation::isFile
 off_t Foam::fileOperations::masterUncollatedFileOperation::fileSize
 (
     const fileName& fName,
+    const bool checkVariants,
     const bool followLink
 ) const
 {
     return masterOp<off_t, fileSizeOp>
     (
         fName,
-        fileSizeOp(followLink),
+        fileSizeOp(checkVariants, followLink),
         Pstream::msgType(),
         comm_
     );
@@ -1011,13 +979,14 @@ off_t Foam::fileOperations::masterUncollatedFileOperation::fileSize
 time_t Foam::fileOperations::masterUncollatedFileOperation::lastModified
 (
     const fileName& fName,
+    const bool checkVariants,
     const bool followLink
 ) const
 {
     return masterOp<time_t, lastModifiedOp>
     (
         fName,
-        lastModifiedOp(followLink),
+        lastModifiedOp(checkVariants, followLink),
         Pstream::msgType(),
         comm_
     );
@@ -1027,13 +996,14 @@ time_t Foam::fileOperations::masterUncollatedFileOperation::lastModified
 double Foam::fileOperations::masterUncollatedFileOperation::highResLastModified
 (
     const fileName& fName,
+    const bool checkVariants,
     const bool followLink
 ) const
 {
     return masterOp<double, lastModifiedHROp>
     (
         fName,
-        lastModifiedHROp(followLink),
+        lastModifiedHROp(checkVariants, followLink),
         Pstream::msgType(),
         comm_
     );
@@ -2415,13 +2385,6 @@ Foam::fileOperations::masterUncollatedFileOperation::NewIFstream
                         << " Opening global file " << filePath << endl;
                 }
 
-                IOstream::compressionType cmp
-                (
-                    Foam::exists(filePath+".gz", false)
-                  ? IOstream::compressionType::COMPRESSED
-                  : IOstream::compressionType::UNCOMPRESSED
-                );
-
                 labelList procs(Pstream::nProcs(Pstream::worldComm)-1);
                 for
                 (
@@ -2433,7 +2396,7 @@ Foam::fileOperations::masterUncollatedFileOperation::NewIFstream
                     procs[proci-1] = proci;
                 }
 
-                readAndSend(filePath, cmp, procs, pBufs);
+                readAndSend(filePath, procs, pBufs);
             }
             else
             {
@@ -2444,20 +2407,7 @@ Foam::fileOperations::masterUncollatedFileOperation::NewIFstream
                     proci++
                 )
                 {
-                    IOstream::compressionType cmp
-                    (
-                        Foam::exists(filePaths[proci]+".gz", false)
-                      ? IOstream::compressionType::COMPRESSED
-                      : IOstream::compressionType::UNCOMPRESSED
-                    );
-
-                    readAndSend
-                    (
-                        filePaths[proci],
-                        cmp,
-                        labelList(1, proci),
-                        pBufs
-                    );
+                    readAndSend(filePaths[proci], labelList(1, proci), pBufs);
                 }
             }
         }
diff --git a/src/OpenFOAM/global/fileOperations/masterUncollatedFileOperation/masterUncollatedFileOperation.H b/src/OpenFOAM/global/fileOperations/masterUncollatedFileOperation/masterUncollatedFileOperation.H
index c5104252ee..024c432388 100644
--- a/src/OpenFOAM/global/fileOperations/masterUncollatedFileOperation/masterUncollatedFileOperation.H
+++ b/src/OpenFOAM/global/fileOperations/masterUncollatedFileOperation/masterUncollatedFileOperation.H
@@ -128,48 +128,52 @@ protected:
 
         class modeOp
         {
+            const bool checkVariants_;
             const bool followLink_;
         public:
-            modeOp(const bool followLink)
+            modeOp(const bool checkVariants, const bool followLink)
             :
+                checkVariants_(checkVariants),
                 followLink_(followLink)
             {}
 
             mode_t operator()(const fileName& fName) const
             {
-                return Foam::mode(fName, followLink_);
+                return Foam::mode(fName, checkVariants_, followLink_);
             }
         };
 
         class typeOp
         {
+            const bool checkVariants_;
             const bool followLink_;
         public:
-            typeOp(const bool followLink)
+            typeOp(const bool checkVariants, const bool followLink)
             :
+                checkVariants_(checkVariants),
                 followLink_(followLink)
             {}
 
             label operator()(const fileName& fName) const
             {
-                return Foam::type(fName, followLink_);
+                return Foam::type(fName, checkVariants_, followLink_);
             }
         };
 
         class existsOp
         {
-            const bool checkGzip_;
+            const bool checkVariants_;
             const bool followLink_;
         public:
-            existsOp(const bool checkGzip, const bool followLink)
+            existsOp(const bool checkVariants, const bool followLink)
             :
-                checkGzip_(checkGzip),
+                checkVariants_(checkVariants),
                 followLink_(followLink)
             {}
 
             bool operator()(const fileName& fName) const
             {
-                return Foam::exists(fName, checkGzip_, followLink_);
+                return Foam::exists(fName, checkVariants_, followLink_);
             }
         };
 
@@ -191,66 +195,82 @@ protected:
 
         class isFileOp
         {
-            const bool checkGzip_;
+            const bool checkVariants_;
             const bool followLink_;
         public:
-            isFileOp(const bool checkGzip, const bool followLink)
+            isFileOp(const bool checkVariants, const bool followLink)
             :
-                checkGzip_(checkGzip),
+                checkVariants_(checkVariants),
                 followLink_(followLink)
             {}
         public:
             bool operator()(const fileName& fName) const
             {
-                return Foam::isFile(fName, checkGzip_, followLink_);
+                return Foam::isFile(fName, checkVariants_, followLink_);
             }
         };
 
         class fileSizeOp
         {
+            const bool checkVariants_;
             const bool followLink_;
         public:
-            fileSizeOp(const bool followLink)
+            fileSizeOp(const bool checkVariants, const bool followLink)
             :
+                checkVariants_(checkVariants),
                 followLink_(followLink)
             {}
 
         public:
             off_t operator()(const fileName& fName) const
             {
-                return Foam::fileSize(fName, followLink_);
+                return Foam::fileSize(fName, checkVariants_, followLink_);
             }
         };
 
         class lastModifiedOp
         {
+            const bool checkVariants_;
             const bool followLink_;
         public:
-            lastModifiedOp(const bool followLink)
+            lastModifiedOp(const bool checkVariants, const bool followLink)
             :
+                checkVariants_(checkVariants),
                 followLink_(followLink)
             {}
 
         public:
             time_t operator()(const fileName& fName) const
             {
-                return Foam::lastModified(fName, followLink_);
+                return Foam::lastModified(fName, checkVariants_, followLink_);
             }
         };
 
         class lastModifiedHROp
         {
+            const bool checkVariants_;
             const bool followLink_;
         public:
-            lastModifiedHROp(const bool followLink)
+            lastModifiedHROp
+            (
+                const bool checkVariants,
+                const bool followLink
+            )
             :
+                checkVariants_(checkVariants),
                 followLink_(followLink)
             {}
 
         public:
             double operator()(const fileName& fName) const
             {
-                return Foam::highResLastModified(fName, followLink_);
+                return
+                    Foam::highResLastModified
+                    (
+                        fName,
+                        checkVariants_,
+                        followLink_
+                    );
             }
         };
 
@@ -352,24 +372,31 @@ protected:
         class readDirOp
         {
             const fileName::Type type_;
-            const bool filtergz_;
+            const bool filterVariants_;
             const bool followLink_;
         public:
             readDirOp
             (
                 const fileName::Type type,
-                const bool filtergz,
+                const bool filterVariants,
                 const bool followLink
             )
             :
                 type_(type),
-                filtergz_(filtergz),
+                filterVariants_(filterVariants),
                 followLink_(followLink)
             {}
 
             fileNameList operator()(const fileName& fName) const
             {
-                return Foam::readDir(fName, type_, filtergz_, followLink_);
+                return
+                    Foam::readDir
+                    (
+                        fName,
+                        type_,
+                        filterVariants_,
+                        followLink_
+                    );
             }
         };
 
@@ -434,15 +461,6 @@ protected:
             const word& instancePath
         ) const;
 
-        //- Read file contents and send to processors
-        static void readAndSend
-        (
-            const fileName& filePath,
-            const IOstream::compressionType cmp,
-            const labelUList& procs,
-            PstreamBuffers& pBufs
-        );
-
         //- Detect file (possibly compressed), read file contents and send
         //  to processors
         static void readAndSend
@@ -508,6 +526,7 @@ public:
             virtual mode_t mode
             (
                 const fileName&,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const;
 
@@ -515,6 +534,7 @@ public:
             virtual fileName::Type type
             (
                 const fileName&,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const;
 
@@ -523,7 +543,7 @@ public:
             virtual bool exists
             (
                 const fileName&,
-                const bool checkGzip=true,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const;
 
@@ -539,7 +559,7 @@ public:
             virtual bool isFile
             (
                 const fileName&,
-                const bool checkGzip=true,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const;
 
@@ -547,6 +567,7 @@ public:
             virtual off_t fileSize
             (
                 const fileName&,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const;
 
@@ -554,6 +575,7 @@ public:
             virtual time_t lastModified
             (
                 const fileName&,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const;
 
@@ -561,6 +583,7 @@ public:
             virtual double highResLastModified
             (
                 const fileName&,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const;
 
@@ -569,7 +592,7 @@ public:
             (
                 const fileName&,
                 const fileName::Type=fileName::FILE,
-                const bool filtergz=true,
+                const bool filterVariants = true,
                 const bool followLink = true
             ) const;
 
diff --git a/src/OpenFOAM/global/fileOperations/uncollatedFileOperation/uncollatedFileOperation.C b/src/OpenFOAM/global/fileOperations/uncollatedFileOperation/uncollatedFileOperation.C
index e0269e76b0..72a5dc8c7a 100644
--- a/src/OpenFOAM/global/fileOperations/uncollatedFileOperation/uncollatedFileOperation.C
+++ b/src/OpenFOAM/global/fileOperations/uncollatedFileOperation/uncollatedFileOperation.C
@@ -206,31 +206,33 @@ bool Foam::fileOperations::uncollatedFileOperation::chMod
 mode_t Foam::fileOperations::uncollatedFileOperation::mode
 (
     const fileName& fName,
+    const bool checkVariants,
     const bool followLink
 ) const
 {
-    return Foam::mode(fName, followLink);
+    return Foam::mode(fName, checkVariants, followLink);
 }
 
 
 Foam::fileName::Type Foam::fileOperations::uncollatedFileOperation::type
 (
     const fileName& fName,
+    const bool checkVariants,
     const bool followLink
 ) const
 {
-    return Foam::type(fName, followLink);
+    return Foam::type(fName, checkVariants, followLink);
 }
 
 
 bool Foam::fileOperations::uncollatedFileOperation::exists
 (
     const fileName& fName,
-    const bool checkGzip,
+    const bool checkVariants,
     const bool followLink
 ) const
 {
-    return Foam::exists(fName, checkGzip, followLink);
+    return Foam::exists(fName, checkVariants, followLink);
 }
 
 
@@ -247,41 +249,44 @@ bool Foam::fileOperations::uncollatedFileOperation::isDir
 bool Foam::fileOperations::uncollatedFileOperation::isFile
 (
     const fileName& fName,
-    const bool checkGzip,
+    const bool checkVariants,
     const bool followLink
 ) const
 {
-    return Foam::isFile(fName, checkGzip, followLink);
+    return Foam::isFile(fName, checkVariants, followLink);
 }
 
 
 off_t Foam::fileOperations::uncollatedFileOperation::fileSize
 (
     const fileName& fName,
+    const bool checkVariants,
     const bool followLink
 ) const
 {
-    return Foam::fileSize(fName, followLink);
+    return Foam::fileSize(fName, checkVariants, followLink);
 }
 
 
 time_t Foam::fileOperations::uncollatedFileOperation::lastModified
 (
     const fileName& fName,
+    const bool checkVariants,
     const bool followLink
 ) const
 {
-    return Foam::lastModified(fName, followLink);
+    return Foam::lastModified(fName, checkVariants, followLink);
 }
 
 
 double Foam::fileOperations::uncollatedFileOperation::highResLastModified
 (
     const fileName& fName,
+    const bool checkVariants,
     const bool followLink
 ) const
 {
-    return Foam::highResLastModified(fName, followLink);
+    return Foam::highResLastModified(fName, checkVariants, followLink);
 }
 
 
diff --git a/src/OpenFOAM/global/fileOperations/uncollatedFileOperation/uncollatedFileOperation.H b/src/OpenFOAM/global/fileOperations/uncollatedFileOperation/uncollatedFileOperation.H
index 91f4622b55..a64c0a7b72 100644
--- a/src/OpenFOAM/global/fileOperations/uncollatedFileOperation/uncollatedFileOperation.H
+++ b/src/OpenFOAM/global/fileOperations/uncollatedFileOperation/uncollatedFileOperation.H
@@ -93,6 +93,7 @@ public:
             virtual mode_t mode
             (
                 const fileName&,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const;
 
@@ -100,6 +101,7 @@ public:
             virtual fileName::Type type
             (
                 const fileName&,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const;
 
@@ -108,7 +110,7 @@ public:
             virtual bool exists
             (
                 const fileName&,
-                const bool checkGzip=true,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const;
 
@@ -124,7 +126,7 @@ public:
             virtual bool isFile
             (
                 const fileName&,
-                const bool checkGzip=true,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const;
 
@@ -132,6 +134,7 @@ public:
             virtual off_t fileSize
             (
                 const fileName&,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const;
 
@@ -139,6 +142,7 @@ public:
             virtual time_t lastModified
             (
                 const fileName&,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const;
 
@@ -146,6 +150,7 @@ public:
             virtual double highResLastModified
             (
                 const fileName&,
+                const bool checkVariants = true,
                 const bool followLink = true
             ) const;
 
diff --git a/src/OpenFOAM/include/OSspecific.H b/src/OpenFOAM/include/OSspecific.H
index 23cc11c4ab..d31a06fc7d 100644
--- a/src/OpenFOAM/include/OSspecific.H
+++ b/src/OpenFOAM/include/OSspecific.H
@@ -100,17 +100,27 @@ bool mkDir(const fileName&, mode_t=0777);
 bool chMod(const fileName&, const mode_t);
 
 //- Return the file mode
-mode_t mode(const fileName&, const bool followLink = true);
+mode_t mode
+(
+    const fileName&,
+    const bool checkVariants = true,
+    const bool followLink = true
+);
 
 //- Return the file type: DIRECTORY or FILE
-fileName::Type type(const fileName&, const bool followLink = true);
+fileName::Type type
+(
+    const fileName&,
+    const bool checkVariants = true,
+    const bool followLink = true
+);
 
 //- Does the name exist (as DIRECTORY or FILE) in the file system?
-//  Optionally enable/disable check for gzip file.
+//  Optionally enable/disable check for variant files.
 bool exists
 (
     const fileName&,
-    const bool checkGzip=true,
+    const bool checkVariants = true,
     const bool followLink = true
 );
 
@@ -118,29 +128,44 @@ bool exists
 bool isDir(const fileName&, const bool followLink = true);
 
 //- Does the name exist as a FILE in the file system?
-//  Optionally enable/disable check for gzip file.
+//  Optionally enable/disable check for variant files.
 bool isFile
 (
     const fileName&,
-    const bool checkGzip=true,
+    const bool checkVariants = true,
     const bool followLink = true
 );
 
 //- Return size of file
-off_t fileSize(const fileName&, const bool followLink = true);
+off_t fileSize
+(
+    const fileName&,
+    const bool checkVariants = true,
+    const bool followLink = true
+);
 
 //- Return time of last file modification
-time_t lastModified(const fileName&, const bool followLink = true);
+time_t lastModified
+(
+    const fileName&,
+    const bool checkVariants = true,
+    const bool followLink = true
+);
 
 //- Return time of last file modification
-double highResLastModified(const fileName&, const bool followLink = true);
+double highResLastModified
+(
+    const fileName&,
+    const bool checkVariants = true,
+    const bool followLink = true
+);
 
 //- Read a directory and return the entries as a string list
 fileNameList readDir
 (
     const fileName&,
     const fileName::Type=fileName::FILE,
-    const bool filtergz=true,
+    const bool filterVariants = true,
     const bool followLink = true
 );
 
diff --git a/src/OpenFOAM/primitives/strings/fileName/fileName.C b/src/OpenFOAM/primitives/strings/fileName/fileName.C
index 8b4008fe2b..2edde81659 100644
--- a/src/OpenFOAM/primitives/strings/fileName/fileName.C
+++ b/src/OpenFOAM/primitives/strings/fileName/fileName.C
@@ -48,9 +48,13 @@ Foam::fileName::fileName(const wordList& lst)
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
-Foam::fileName::Type Foam::fileName::type(const bool followLink) const
+Foam::fileName::Type Foam::fileName::type
+(
+    const bool checkVariants,
+    const bool followLink
+) const
 {
-    return ::Foam::type(*this, followLink);
+    return ::Foam::type(*this, checkVariants, followLink);
 }
 
 
diff --git a/src/OpenFOAM/primitives/strings/fileName/fileName.H b/src/OpenFOAM/primitives/strings/fileName/fileName.H
index 09c491bb89..0e8e8a40b8 100644
--- a/src/OpenFOAM/primitives/strings/fileName/fileName.H
+++ b/src/OpenFOAM/primitives/strings/fileName/fileName.H
@@ -156,7 +156,11 @@ public:
 
             //- Return the file type: FILE, DIRECTORY, UNDEFINED or
             //  LINK (only if followLink=false)
-            Type type(const bool followLink = true) const;
+            Type type
+            (
+                const bool checkVariants = true,
+                const bool followLink = true
+            ) const;
 
             //- Return true if file name is absolute
             bool isAbsolute() const;
diff --git a/src/triSurface/triSurface/interfaces/STL/readSTLBINARY.C b/src/triSurface/triSurface/interfaces/STL/readSTLBINARY.C
index 5a0b01cfa3..28c50a6b7c 100644
--- a/src/triSurface/triSurface/interfaces/STL/readSTLBINARY.C
+++ b/src/triSurface/triSurface/interfaces/STL/readSTLBINARY.C
@@ -43,7 +43,7 @@ bool Foam::triSurface::readSTLBINARY(const fileName& STLfileName)
     );
 
     // If the file is compressed, decompress it before reading.
-    if (!STLfilePtr->good() && isFile(STLfileName + ".gz", false))
+    if (!STLfilePtr->good() && isFile(STLfileName + ".gz", false, false))
     {
         compressed = true;
         STLfilePtr.reset(new igzstream((STLfileName + ".gz").c_str()));