diff --git a/bin/pg_backrest b/bin/pg_backrest
index fdf469ef5..6e76604ae 100755
--- a/bin/pg_backrest
+++ b/bin/pg_backrest
@@ -80,7 +80,7 @@ eval
             protocolTimeoutGet()
         );
 
-        # !!! Would like to remove this check and allow a test lock
+        # ??? Would like to remove this check and allow a test lock
         if (optionGet(OPTION_COMMAND) ne 'test' && !optionTest(OPTION_PROCESS))
         {
             lockAcquire(optionGet(OPTION_COMMAND), undef, true, optionGet(OPTION_PROCESS, false));
diff --git a/doc/lib/BackRestDoc/Common/DocRender.pm b/doc/lib/BackRestDoc/Common/DocRender.pm
index 1f9044558..ad4543591 100644
--- a/doc/lib/BackRestDoc/Common/DocRender.pm
+++ b/doc/lib/BackRestDoc/Common/DocRender.pm
@@ -452,7 +452,7 @@ sub process
             $strBuffer = ('#' x $iDepth) . ' `' . $oDoc->paramGet('id') . '` ' . $strTitle;
         }
 
-        # Try to get the title param from the element (!!! this is the old style and should be removed)
+        # Try to get the title param from the element (??? this is the old style and should be removed)
         my $strTitle = $oDoc->paramGet('title', false);
 
         if (!defined($strTitle))
diff --git a/lib/BackRest/Archive.pm b/lib/BackRest/Archive.pm
index a286b1df0..70b80e99d 100644
--- a/lib/BackRest/Archive.pm
+++ b/lib/BackRest/Archive.pm
@@ -384,8 +384,8 @@ sub get
     # If the destination file path is not absolute then it is relative to the db data path
     if (index($strDestinationFile, '/',) != 0)
     {
-        # !!! If db-path is required this is can be removed.
-        # !!! db-path should be added as a requirement for the remote settings work.
+        # ??? If db-path is required this is can be removed.
+        # ??? db-path should be added as a requirement for the remote settings work.
         if (!optionTest(OPTION_DB_PATH))
         {
             confess &log(ERROR, 'option db-path must be set when relative xlog paths are used');
diff --git a/lib/BackRest/Common/Log.pm b/lib/BackRest/Common/Log.pm
index e46b8f525..9d3ea2894 100644
--- a/lib/BackRest/Common/Log.pm
+++ b/lib/BackRest/Common/Log.pm
@@ -286,7 +286,7 @@ sub logDebugProcess
         {
 
             # If the parameter is a hash but not blessed then represent it as a string
-            # !!! This should go away once the inputs to logDebug can be changed
+            # ??? This should go away once the inputs to logDebug can be changed
             if (ref($oValue) eq 'HASH' && !blessed($oValue))
             {
                 $$oParamHash{$strParamName}{value} = '[hash]';
diff --git a/lib/BackRest/File.pm b/lib/BackRest/File.pm
index 6d5436f55..8741a56ed 100644
--- a/lib/BackRest/File.pm
+++ b/lib/BackRest/File.pm
@@ -312,7 +312,7 @@ sub pathTypeGet
 
 ####################################################################################################################################
 # pathGet
-# !!! Need ot tackle the return paths in this function
+# ??? Need to tackle the return paths in this function (i.e. there are to many ways to return)
 ####################################################################################################################################
 sub pathGet
 {
@@ -528,7 +528,7 @@ sub linkCreate
     else
     {
         # If the destination path is backup and does not exist, create it
-        # !!! This should only happen when the link create errors
+        # ??? This should only happen when the link create errors
         if ($bPathCreate && $self->pathTypeGet($strDestinationPathType) eq PATH_BACKUP)
         {
             $self->pathCreate(PATH_BACKUP_ABSOLUTE, dirname($strDestination));
diff --git a/lib/BackRest/Protocol/IO.pm b/lib/BackRest/Protocol/IO.pm
index b588a7c4f..5fd2807e3 100644
--- a/lib/BackRest/Protocol/IO.pm
+++ b/lib/BackRest/Protocol/IO.pm
@@ -202,7 +202,7 @@ sub lineRead
             # Else the buffer is empty and data will need to be loaded
             else
             {
-                undef($self->{strBuffer});  # !!! Do we need this?
+                undef($self->{strBuffer});  # ??? Do we need this?
                 $self->{iBufferSize} = 0;
                 $self->{iBufferPos} = 0;
             }