Currently, the only customization that can be performed is using HyperlinkToolTipFormatString property of RadRichTextBox, which sets the format for all hyperlinks in the document of the control. It would be nice if it were possible to be able to set different tooltips. 

When the content of an entire row is copied and the caret is inserted in the left most column of a row, then the content of each cell in that row should be overwritten with the contents in the clipboard when pasted.

When such content is pasted just after a table, new row is added and filled with values.

When such content is pasted in paragraph, new table is created.

Add a property that can control whether a table row is allowed to break across pages or not.

Currently HtmlFormatProvider does not export/import tables with alignment (left, center, right).

Check all possible shorthand properties, e.g. border-[left/top/right/bottom]. Also check CSS properties like border-[left/top/right/bottom]-[color/style/width].

Add support for All Capitals (All caps) and Small Capitals (Small caps) run property. MS Word has such option in Home -> Font -> Dialog Launcher -> Font -> All Caps/Small Caps.

All letters of such runs are visualized as capital letters.

The corresponding elements in OOXML are <w:caps /> and <w:smallcaps />.

When text is using fonts with defined ligatures (e.g. Calibri, Gabriola, etc.) and contains character groups with defined ligature for it, the text width is measured incorrectly (shorter that it should be). As caret and selection navigates on positions computed by this measuring system, they are not synchronized with what is shown in the UI (which correctly respects the ligatures), and there is slight offset from the real character positions and/or clipping of part of the letters at the end of the line.

Examples of such groups are (depending on the font) "tt", "ff", "ffi".

In MS Word, for example, when you "Save as" PDF, you can choose "options" -> Encrypt the document with a password.

If RadRichTextBox contains a table and is placed in a window and then the window is resized horizontally, the table border are moved unexpectedly and change their place relative to the content of the documen. If the window is maximized and/or restored, some of the borders disappear.

Workaround: Execute the following code snippet in window's or RadRichTextBox' SizeChanged event handler:
if (this.MyRadRichTextBox.ActiveEditorPresenter != null)
{
    this.MyRadRichTextBox.ActiveEditorPresenter.RecreateUI();
}

Add support for = (Formula) fields, including the scenario with referencing other table cells.

More information: https://support.office.com/en-us/article/Field-codes-Formula-field-32d5c9de-3516-4ec3-80ed-d1fc2b5bc21d?ui=en-US&rs=en-US&ad=US

Implement nested mail merge - creating mail merge reports using master-detail tables in a data source.

Typical example of this is creating an invoices with mail merge, where each invoice contains a list of items.

Workaround: for some scenarios creating custom merge field which evaluates to Table could simulate this behavior:
http://www.telerik.com/forums/merge-reports#lUdH39ww00SnEhTLLlrXwA

Handwriting keyboard allows you to enter text with a pen or other stylus. This is currently not implemented in RichTextBox and when you are using handwriting keyboard, the text is inserted more than once when the stylus is lifted while writing.

Implement an option for controlling how the list-style-type of a list will be exported to the HTML format.

The default indentation of the list bullets is different when shown in the RadRichTextBox and when exported to HTML and shown in a web browser.
There is a screenshot attached showing how the result is rendered in a web browser.

After further discussion within the XAML team and more research, we decided that introducing a similar property does not align with the current idea and model of RadRichTextBox. Thus, we are declining this item.

RadDocument instances leak when editing a document containing a field and header/footer. The StyleRepository holds a reference to a style's document element.

Fix available in LIB Version 2017.3.1002.

Processing hangs on HTML import when the html file contains large base64 images. 

Expose events that are fired when the internal document commands are executed. 

Currently, custom bibliographic styles are not applied to the document when imported. Introducing an event will allow the user to provide the custom bibliographic style implementation and apply it to the document.

While clicking to position the caret at the beginning of a paragraph, the caret is jumping to the previous document position and returning back to the desired one. 

Fix available in LIB Version 2017.2.627.