Using the RadDocumentEditor class, the users can change the margin of the current section. However, there isn't a method allowing them to change the default section margin of the document. 

In MS Word, there is an option to show gridlines over the pages of the document. Implement such an option in RadRichTextBox as well.

Workaround: The attached project offers a simple custom implementation.

If you insert a picture in a RichTextBox in web layout mode and stretch it to exceed the boundaries of the control (set a smaller size to make it more convenient), a horizontal scrollbar will appear. If you do the same, but with the picture in a table, the scrollbar will not appear.

Currently, the whole document is kept in memory. In some cases, this creates too much of a memory footprint (even exceeding the usable ~1.2 GB of a .NET process) and causes an OutOfMemoryException. For example, a document with around 2000 pages will fail on import. 



Optimize how style properties are used. Default style properties could be shared among all elements of the same type who does not have any local values.

Currently, span elements can only have highlight color and paragraphs can have a background(shading). In MS Word it is possible to apply a background to spans. The import of such a document removes the formatting.

Add support for positioning floating images relative to section columns. Currently, such images are laid out relative to the first column.

The customers need to additionally process the elements after inserting them into the document or just change the caret position relative to the inserted element. At this point, the methods only insert elements without returning the concrete instance or copy the element passed as a parameter, if such overload is available (editor.InsertTable(table) clones the table and inserts a different instance in the document).

According to the RTF Specification, each bookmark start should have a matching bookmark end. However, when opening a document which contains bookmark start without bookmark end, MS Word treats the start position for an end as well and successfully opens the document. When such document is being imported in RadRichTextBox, an InvalidCastException is thrown.

In MS Word, the users can add a source for the mail merge operation using the Select Recipients option. In the menu, they can import a file containing the data. Expose a similar option in RadRichTextBox as well.

The bolder keyword is currently not supported. In the CSS, setting bolder means one font weight heavier than the parent element, so if the parent is with font-weight, font-weight: bolder would mean that the content should be with normal font weight. In MS Word, this value is imported as bold no matter of the parent's value.

Implement import and export of OpenDocument files (.odt).

In MS Word, when track changes are enabled, the users can choose to show the revisions in balloons, similar to comments. Add such possibility in RadRichTextBox as well.

Import description lists: <dl>, <dt>, <dd> tags.

Possible way for implementation is with paragraphs with left margin.

API ideas:

- DocumentSelection: Get inlines between annotation start and end, e.g. DocumentSelection.EnumerateChildrenOfType<>(bool includePartiallySelectedElements) where T : DocumentElement

- DocumentSelection: SelectAnnotationRange(AnnotationRangeStart start, bool includeAnnotation). Such method is present without the last parameter, but it always selects the annotation ranges

When pressing Shift+Up(Down) should create a selection to the start(end) of the document when the caret position is on the first(last) line. Currently, in this case, a selection is not created.

Such behavior can be achieved using the following approach:

        private void RadRichTextBox_CommandExecuting(object sender, CommandExecutingEventArgs e)
        {
            if (e.Command is MoveCaretCommand && System.Windows.Input.Keyboard.Modifiers == ModifierKeys.Shift)
            {
                var command = e.Command as MoveCaretCommand;
                MoveCaretDirections direction = (MoveCaretDirections)e.CommandParameter;
                if (direction == MoveCaretDirections.Up)
                {
                    var positionOnFirstLine = new DocumentPosition(this.radRichTextBox.Document);
                    positionOnFirstLine.MoveToFirstPositionInDocument();
                    if (this.radRichTextBox.Document.CaretPosition.Location.Y - positionOnFirstLine.Location.Y < 1)
                    {
                        this.radRichTextBox.Document.CaretPosition.MoveToPosition(positionOnFirstLine);
                        e.Cancel = true;
                    }
                }
                else if (direction == MoveCaretDirections.Down)
                {
                    var positionOnLastLine = new DocumentPosition(this.radRichTextBox.Document);
                    positionOnLastLine.MoveToLastPositionInDocument();
                    if (positionOnLastLine.Location.Y - this.radRichTextBox.Document.CaretPosition.Location.Y < 1)
                    {
                        this.radRichTextBox.Document.CaretPosition.MoveToPosition(positionOnLastLine);
                        e.Cancel = true;
                    }
                }
            }
        }

At this point, the FloatingUIContainers cannot be selected. Implement selection to enable the users to work easily with such elements.

This would enable the customers to track the content that is being inserted and decline its insertion if needed.

At the moment the table properties, including table, table row and table cell properties don't have size validation, i.e. it is possible to set them to negative or zero values. Validation should be added where necessary.

Currently RadRichTextBox uses the .NET syntax for the date and time formatting of the code fields. When such strings are exported to or imported from RTF/DOCX, the date and time formatting switch should be converted according to the document format specifications (e.g. 17.16.4.1 Date and time formatting from OOXML specification). Examples of differences:

- 'tt' in .NET is converted to am/pm specifier for the current culture. In DOCX specification, this is denoted as 'am/pm'
- '/' in .NET is converted to date separator for the current culture. In DOCX specification, the symbol doesn't have special meaning, so it's always converted to '/'.

.NET date format strings: https://docs.microsoft.com/en-us/dotnet/standard/base-types/custom-date-and-time-format-strings

MS Word date format strings: 
https://support.office.com/en-us/article/insert-edit-and-view-fields-in-word-c429bbb0-8669-48a7-bd24-bab6ba6b06bb#bm9

Workaround (partial): Modify InsertDateTimeDialog to contain only formats which are compatible with MS Word.

The 'white-space' CSS property determines how whitespace inside an element is handled. The 'pre' value preserves the sequences of whitespaces and the newlines in the element content.

This property value is supported by MS Word.