diff --git a/lib/redmine_dmsf/webdav/base_resource.rb b/lib/redmine_dmsf/webdav/base_resource.rb
index e283bad1..2aec20d6 100644
--- a/lib/redmine_dmsf/webdav/base_resource.rb
+++ b/lib/redmine_dmsf/webdav/base_resource.rb
@@ -60,8 +60,8 @@ module RedmineDmsf
         @public_path.force_encoding('utf-8')
       end
 
-      # Generate HTML for Get requests
-      def html_display
+      # Generate HTML for Get requests, or Head requests if no_body is true
+      def html_display(no_body = false)
         @response.body = ''
         Confict unless collection?        
         entities = children.map{|child| 
@@ -80,7 +80,7 @@ module RedmineDmsf
           '',
           '',
         ] + entities if parent        
-        @response.body << index_page % [ path.empty? ? '/' : path, path.empty? ? '/' : path, entities ]
+        @response.body << index_page % [ path.empty? ? '/' : path, path.empty? ? '/' : path, entities ] unless no_body
       end
 
       # Run method through proxy class - ensuring always compatible child is generated      
diff --git a/lib/redmine_dmsf/webdav/controller.rb b/lib/redmine_dmsf/webdav/controller.rb
index 750d5aea..446b9d8c 100644
--- a/lib/redmine_dmsf/webdav/controller.rb
+++ b/lib/redmine_dmsf/webdav/controller.rb
@@ -27,6 +27,36 @@ module RedmineDmsf
     class Controller < DAV4Rack::Controller
       include DAV4Rack::Utils
 
+      # Return response to OPTIONS
+      def options
+        # exist? returns false if user is anonymous for ProjectResource and DmsfResource, but not for IndexResource.
+        unless(resource.exist? || (User.current && User.current.anonymous?))
+          # Return NotFound if resource does not exist and the request is not anonymous.
+          NotFound
+        else
+          if request.env.has_key?('HTTP_X_OFFICE_MAJOR_VERSION') && User.current && User.current.anonymous?
+            # Anonymous request from MsOffice, respond 405.
+            # If responding with 401 then MsOffice will fail.
+            # If responding with 200 then MsOffice will think that anonymous access is ok for everything.
+            # Responding with 405 is a workaround found in https://support.microsoft.com/en-us/kb/2019105
+            MethodNotAllowed
+          else
+            resource.options
+          end
+        end
+      end
+
+      # Return response to HEAD
+      def head
+        # exist? returns false if user is anonymous for ProjectResource and DmsfResource, but not for IndexResource.
+        unless(resource.exist? || (request.env.has_key?('HTTP_X_OFFICE_MAJOR_VERSION') && User.current && User.current.anonymous?))
+          # Return NotFound if resource does not exist and the request is not from an anonymous MsOffice product.
+          NotFound
+        else
+          resource.head(request, response)
+        end
+      end
+
       # Return response to PROPFIND
       def propfind
         unless(resource.exist?)
diff --git a/lib/redmine_dmsf/webdav/dmsf_resource.rb b/lib/redmine_dmsf/webdav/dmsf_resource.rb
index 4d1fa833..a19397ab 100644
--- a/lib/redmine_dmsf/webdav/dmsf_resource.rb
+++ b/lib/redmine_dmsf/webdav/dmsf_resource.rb
@@ -53,7 +53,7 @@ module RedmineDmsf
       # Our already quite heavy usage of DB would just get silly every time we called
       # this method.
       def children
-        unless @childern
+        unless @children
           @children = []
           if collection?
             folder.dmsf_folders.select(:title).visible.map do |p|
@@ -195,6 +195,23 @@ module RedmineDmsf
         OK
       end
 
+      # Process incoming HEAD request
+      #
+      # MsOFfice uses anonymous HEAD requests, so always return a response.
+      # See https://support.microsoft.com/en-us/kb/2019105
+      ##
+      def head(request, response)
+        raise NotFound unless project && project.module_enabled?('dmsf') && (folder || file)
+        
+        if collection?
+          html_display(true)
+          response['Content-Length'] = response.body.bytesize.to_s
+        else
+          response.body = ''
+        end
+        OK
+      end
+
       # Process incoming MKCOL request
       #
       # Create a DmsfFolder at location requested, only if parent is a folder (or root)
@@ -227,7 +244,19 @@ module RedmineDmsf
       def delete
         if file
           raise Forbidden unless User.current.admin? || User.current.allowed_to?(:file_delete, project)
-          file.delete(false) ? NoContent : Conflict
+          if file.name.match(/.\.tmp$/i)
+            # .tmp files should be destroyed (MsOffice file)
+            destroy = true
+          elsif file.name.match(/^\~\$/i)
+            # Files starting with ~$ should be destroyed (MsOffice file)
+            destroy = true
+          elsif file.last_revision.size == 0
+            # Zero-sized files should be destroyed
+            destroy = true
+          else
+            destroy = false
+          end
+          file.delete(destroy) ? NoContent : Conflict
         elsif folder
           raise Forbidden unless User.current.admin? || User.current.allowed_to?(:folder_manipulation, project)
           folder.delete(false) ? NoContent : Conflict
@@ -298,8 +327,8 @@ module RedmineDmsf
               # Save
               new_revision.save && resource.file.save
 
-              # Delete the file that should have been renamed.
-              file.delete(false) ? NoContent : Conflict
+              # Delete (and destroy) the file that should have been renamed and return what should have been returned in case of a copy
+              file.delete(true) ? Created : PreconditionFailed
             else
               # Files cannot be merged at this point, until a decision is made on how to merge them
               # ideally, we would merge revision history for both, ensuring the origin file wins with latest revision.
@@ -526,6 +555,7 @@ module RedmineDmsf
         end
 
         new_revision = DmsfFileRevision.new
+        reuse_revision = false
 
         if exist? # We're over-writing something, so ultimately a new revision
           f = file
@@ -533,6 +563,7 @@ module RedmineDmsf
           if last_revision.size == 0
             new_revision = last_revision
             new_revision.minor_version -= 1
+            reuse_revision = true
           else
             new_revision.source_revision = last_revision
             if last_revision
@@ -574,7 +605,7 @@ module RedmineDmsf
         
         raise InternalServerError unless new_revision.valid? && f.save
 
-        new_revision.disk_filename = new_revision.new_storage_filename
+        new_revision.disk_filename = new_revision.new_storage_filename unless reuse_revision
 
         if new_revision.save
           new_revision.copy_file_content(request.body)
@@ -610,6 +641,13 @@ module RedmineDmsf
         end
       end
 
+      def options_req
+        response["Allow"] = 'OPTIONS,HEAD,GET,PUT,POST,DELETE,PROPFIND,PROPPATCH,MKCOL,COPY,MOVE,LOCK,UNLOCK'
+        response["Dav"] = '1, 2'
+        response["Ms-Author-Via"] = "DAV"
+        OK
+      end
+
       private
       # Prepare file for download using Rack functionality:
       # Download (see RedmineDmsf::Webdav::Download) extends Rack::File to allow single-file
diff --git a/lib/redmine_dmsf/webdav/index_resource.rb b/lib/redmine_dmsf/webdav/index_resource.rb
index 3eef7c21..10cf320a 100644
--- a/lib/redmine_dmsf/webdav/index_resource.rb
+++ b/lib/redmine_dmsf/webdav/index_resource.rb
@@ -69,12 +69,26 @@ module RedmineDmsf
         4096
       end
 
+      def head(request, response)
+        html_display(true)
+        response['Content-Length'] = response.body.bytesize.to_s
+        OK
+      end
+
       def get(request, response)
         html_display
         response['Content-Length'] = response.body.bytesize.to_s
         OK
       end
 
+      def options_req
+        response["Allow"] = 'OPTIONS,HEAD,GET,PUT,POST,DELETE,PROPFIND,PROPPATCH,MKCOL,COPY,MOVE,LOCK,UNLOCK'
+        #response["Allow"] = 'OPTIONS,PROPFIND'
+        response["Dav"] = '1, 2'
+        response["Ms-Author-Via"] = "DAV"
+        OK
+      end
+
       # Bugfix: Ensure that this level never indicates a parent
       def parent
         nil
diff --git a/lib/redmine_dmsf/webdav/project_resource.rb b/lib/redmine_dmsf/webdav/project_resource.rb
index a99f1b6d..41a67428 100644
--- a/lib/redmine_dmsf/webdav/project_resource.rb
+++ b/lib/redmine_dmsf/webdav/project_resource.rb
@@ -85,12 +85,30 @@ module RedmineDmsf
         4096
       end
 
+      def head(request, response)
+        # HEAD must be allowed even for anonymous users, so just verify that the project exists and that the dmsf module is enabled.
+        if project.nil? || !project.module_enabled?('dmsf')
+          NotFound
+        else
+          html_display(true)
+          response['Content-Length'] = response.body.bytesize.to_s
+          OK        
+        end
+      end
+
       def get(request, response)
         html_display
         response['Content-Length'] = response.body.bytesize.to_s
         OK
       end
 
+      def options_req
+        response["Allow"] = 'OPTIONS,HEAD,GET,PUT,POST,DELETE,PROPFIND,PROPPATCH,MKCOL,COPY,MOVE,LOCK,UNLOCK'
+        response["Dav"] = '1, 2'
+        response["Ms-Author-Via"] = "DAV"
+        OK
+      end
+
       def folder
         nil
       end
@@ -100,4 +118,4 @@ module RedmineDmsf
 
     end
   end
-end
\ No newline at end of file
+end
diff --git a/lib/redmine_dmsf/webdav/resource_proxy.rb b/lib/redmine_dmsf/webdav/resource_proxy.rb
index a87945c3..3675c931 100644
--- a/lib/redmine_dmsf/webdav/resource_proxy.rb
+++ b/lib/redmine_dmsf/webdav/resource_proxy.rb
@@ -51,7 +51,13 @@ module RedmineDmsf
         # going to fork it to ensure compliance, checking the request method in the authentication
         # seems the next best step, if the request method is OPTIONS return true, controller will simply
         # call the options method within, which accesses nothing, just returns headers about dav env.
-        return true if @request.request_method.downcase == 'options' && (path == '/' || path.empty?)
+        #return true if @request.request_method.downcase == 'options' && (path == '/' || path.empty?)
+
+        # Allow anonymous OPTIONS requests.
+        return true if @request.request_method.downcase == 'options'
+        # Allow anonymous HEAD requests.
+        return true if @request.request_method.downcase == 'head'
+
         return false unless username && password
         User.current = User.try_to_login(username, password)
         return User.current && !User.current.anonymous?
@@ -93,6 +99,10 @@ module RedmineDmsf
         @resource_c.content_length
       end
 
+      def head(request,response)
+        @resource_c.head(request, response)
+      end
+
       def get(request, response)
         @resource_c.get(request, response)
       end
@@ -153,6 +163,9 @@ module RedmineDmsf
         @resource_c.properties
       end
 
+      def options
+        @resource_c.options_req
+      end
     end
   end
 end