diff --git a/src/OSspecific/POSIX/POSIX.C b/src/OSspecific/POSIX/POSIX.C
index 1ec27351d..2b388cd15 100644
--- a/src/OSspecific/POSIX/POSIX.C
+++ b/src/OSspecific/POSIX/POSIX.C
@@ -555,6 +555,7 @@ bool Foam::chMod(const fileName& name, const mode_t m)
 }
 
 
+// Return the file mode
 mode_t Foam::mode(const fileName& name)
 {
     fileStat fileStatus(name);
@@ -569,6 +570,7 @@ mode_t Foam::mode(const fileName& name)
 }
 
 
+// Return the file type: FILE or DIRECTORY
 Foam::fileName::Type Foam::type(const fileName& name)
 {
     mode_t m = mode(name);
@@ -588,24 +590,28 @@ Foam::fileName::Type Foam::type(const fileName& name)
 }
 
 
+// Does the name exist in the filing system?
 bool Foam::exists(const fileName& name, const bool checkGzip)
 {
     return mode(name) || isFile(name, checkGzip);
 }
 
 
+// Does the directory exist?
 bool Foam::isDir(const fileName& name)
 {
     return S_ISDIR(mode(name));
 }
 
 
+// Does the file exist?
 bool Foam::isFile(const fileName& name, const bool checkGzip)
 {
     return S_ISREG(mode(name)) || (checkGzip && S_ISREG(mode(name + ".gz")));
 }
 
 
+// Return size of file
 off_t Foam::fileSize(const fileName& name)
 {
     fileStat fileStatus(name);
@@ -620,6 +626,7 @@ off_t Foam::fileSize(const fileName& name)
 }
 
 
+// Return time of last file modification
 time_t Foam::lastModified(const fileName& name)
 {
     fileStat fileStatus(name);
@@ -634,6 +641,7 @@ time_t Foam::lastModified(const fileName& name)
 }
 
 
+// Read a directory and return the entries as a string list
 Foam::fileNameList Foam::readDir
 (
     const fileName& directory,
@@ -729,6 +737,7 @@ Foam::fileNameList Foam::readDir
 }
 
 
+// Copy, recursively if necessary, the source to the destination
 bool Foam::cp(const fileName& src, const fileName& dest)
 {
     // Make sure source exists.
@@ -828,6 +837,7 @@ bool Foam::cp(const fileName& src, const fileName& dest)
 }
 
 
+// Create a softlink. dst should not exist. Returns true if successful.
 bool Foam::ln(const fileName& src, const fileName& dst)
 {
     if (POSIX::debug)
@@ -865,6 +875,7 @@ bool Foam::ln(const fileName& src, const fileName& dst)
 }
 
 
+// Rename srcFile dstFile
 bool Foam::mv(const fileName& src, const fileName& dst)
 {
     if (POSIX::debug)
@@ -890,6 +901,8 @@ bool Foam::mv(const fileName& src, const fileName& dst)
 }
 
 
+//- Rename to a corresponding backup file
+//  If the backup file already exists, attempt with "01" .. "99" index
 bool Foam::mvBak(const fileName& src, const std::string& ext)
 {
     if (POSIX::debug)
@@ -927,6 +940,8 @@ bool Foam::mvBak(const fileName& src, const std::string& ext)
 }
 
 
+
+// Remove a file, returning true if successful otherwise false
 bool Foam::rm(const fileName& file)
 {
     if (POSIX::debug)
@@ -947,6 +962,7 @@ bool Foam::rm(const fileName& file)
 }
 
 
+// Remove a dirctory and its contents
 bool Foam::rmDir(const fileName& directory)
 {
     if (POSIX::debug)
@@ -1236,7 +1252,7 @@ bool Foam::dlSymFound(void* handle, const std::string& symbol)
     }
 }
 
-
+#ifdef NOT_SURE_HOW_TO_USE_THIS
 static int collectLibsCallback
 (
     struct dl_phdr_info *info,
@@ -1263,6 +1279,7 @@ Foam::fileNameList Foam::dlLoaded()
     }
     return libs;
 }
+#endif
 
 
 void Foam::osRandomSeed(const label seed)