This property allows the user to set the transparency of the image watermark. In the OOXML, the property is written using the 'blacklevel' attribute of the image.

Introduce Split Table Command. 

In MS Word, the command is in Table Tools -> Layout -> Merge -> Split table.

Workaround: Use the RadDocumentEditor API to split the table:
 
var tableRowBox = this.radRichTextBox.Document.CaretPosition.GetCurrentTableRowBox();
if (tableRowBox != null)
{
    this.radRichTextBox.BeginUndoGroup();

    this.radRichTextBox.Document.Selection.Clear();

    var currentRow = tableRowBox.AssociatedTableRow;

    DocumentPosition start = new DocumentPosition(currentRow.GetRootDocument());
    start.MoveToStartOfDocumentElement(currentRow);

    DocumentPosition end = new DocumentPosition(start);
    end.MoveToEndOfDocumentElement(currentRow.Table.Rows.Last);

    this.radRichTextBox.Document.Selection.SetSelectionStart(start);
    this.radRichTextBox.Document.Selection.AddSelectionEnd(end);

    this.radRichTextBox.Cut();

    this.radRichTextBox.InsertParagraph();
    this.radRichTextBox.Paste();

    this.radRichTextBox.EndUndoGroup("Split table");
}
 

Add support for math type equations.

Command that converts currently selected text to sentence case, lowercase, uppercase, capitalizes each word, or toggles case, while preserving the styling. A sample demonstrating how to add a custom implementation of a similar command is attached.

Include import and export in open XML - (<w:caps /> property in run properties) and in HTML (text-transform property).

Implement support for exact table row height option. By using this option the text should be clipped when the table row height is lower than the height needed for the text to render. 
The current implementation supports only the at least option.

Add support for importing/exporting macro-enabled document (*.dotm), while preserving the macro content.

Adding support for exporting font style as font tag. Android's TextView for example support styling only using tags.

Currently invalid attribute values, including invalid or empty values in CSS attributes in the 'style' attribute, could cause importing property with incorrect value, or NullReferenceException (the document cannot be imported).
Examples:
----------------------------------------------------------
<table width=”*”>
	<tr>
		<td>More Random Text</td>
	</tr>
</table>

The table is imported with 0 width. Instead the width should not be set.
----------------------------------------------------------
<table style="font-size:;">
	<tr>
		<td>More Random Text</td>
	</tr>
</table>

NullReferenceException is thrown.
----------------------------------------------------------

Workaround: replace the invalid values before import:
string importString = html.Replace("font-style: ;", "");

The unit that is used by default is px. Allow modification to the default unit, say pt.

The thmx file extension is associated with Microsoft Office 2007/2010 themes.The themes are stored in *.thmx files, and the built-in Office themes are stored this way in C:\Program Files\Microsoft Office\Document Themes 12\.

The format of a thmx file itself is a ZIP-based format (just like the OpenXML file format).
With the use of the thmx templates, it is possible for users to create uniform looking documents in Word (also in Excel and PowerPoint).

Workaround: Currently, exporting of RadDocument style sheet is supported only to custom XAML format (http://docs.telerik.com/devtools/wpf/controls/radrichtextbox/features/styles/style-sheets ).

Add ability to combine revisions from different authors into a single document.

Add ability to select last paragraph symbol in Section and TableCell.  Currently there is no document position after the last paragraph symbol in a document/section/table cell. This means it cannot be part of a DocumentSelection.

When doing word-by-word spell checking, the spell checking dialog sometimes covers the misspelled word, so the user cannot see the context of the word without manually moving the dialog. It would be nice if there was a way to change the position of the dialog while spell checking so that it doesn't cover the context of the word.

Add Paragraph property controlling  whether SpacingBefore / SpacingAfter is applied between paragraphs with the same style.

In MS Word, the corresponding option is controlled with "Don't add space between paragraphs of the same style" checkbox in the font properties dialog - and the paragraph spacing after will not be applied. 

In OOXML, it is described with the w:contextualSpacing element. We don't respect this property on import of such files, and the paragraph spacing is bigger.

Common use case for this feature is that when list is applied to multiple paragraphs, Paragraph List style is applied to the items, and this style has "Don't add space between paragraphs of the same style" applied, so the vertical spacing between the items is smaller.

Currently Find dialog searches only in the editor from which it's started, e.g. if the user presses Ctrl+F in a comment, only the text of this comment is searched.

Add full support for spell checking of comments. Currently the words are not underlined, and the user cannot show the suggestions in the context menu; but it can trigger the spell checking dialog from the UI command.

Check if this is possible for other child editors like footnotes/endnotes.

In MS Word the users have the ability to embed different objects and files in the document, using the Insert tab -> Text section -> Object. Implement similar behavior in RadRichTextBox, allowing to embed objects as inlines, to edit them, and to re-embed them after editing.

Multi-byte Unicode characters can be represented as multiple ANSI characters in the form \'xx, for example:
\'89\'ce can represent the character 火 if multi-byte encoding should be used. Using multi-byte encoding could be set explicitly using the \ucN tag, or implicitly using the \fcharset for the current font (e.g. \fcharset134 is double-byte).

When such text is imported (commonly CJK text [Chinese, Korean, Japanese] the characters are imported incorrectly (as two '?' or as two different characters for each character)

Such RTF documents are produced from Office 2010 (Word, Outlook), WordPad - on saving or on copying content from the applications.

Such behavior is observed when copying text from WPS Writer (version 11.2.0.10132) Part of WPS Office.

We could export the image absolute position as CSS style, for example: ".img{position: absolute;left: 100px;top: 150px;}"

Additionally we could export the left, top, right and bottom margins of the image, as we already have this information in the model.

A digital signature can be used to authenticate the identity of a user and the document’s contents.